Need advice/help with engine build...

So a while back before I moved to Baltimore, I had started this project. Due to circumstances surrounding the move it got sidetracked as projects tend to do. Now I'm looking to get the ball rolling but I need a little advice/motivation/help. I always have trouble making decisions when it comes to spending money and this project is no exception. This post may get a little long, but I understand detail is important. Keep in mind I had no idea what I was doing when I started this and I'm not much better off now.

What I have:
I have a 1971 Ford Maverick. It is a light car with a curb weight of about 2850lbs. Currently using a C4 automatic trans but long term goal is an AOD or T5. Right now it has an 8” rear with 3.00 gears but I’m also working on an 8.8” rear with limited slip and 3.73 gears.

I started with a 5.0HO from a junkyard 1993 Thunderbird. This was completely torn down. Two scored rod bearings so the crank was turned and polished. Will need remeasured as the shop (Work seems good, communication lacking) did not provide the exact specs, so I don't know what size bearings to order. They estimated 0.010" required. Didn't look that bad. Block was solid but cylinders were out of round enough that they recommended boring. Choose 0.030" over as it seems pretty common to keep options for parts open. Have the stock roller camshaft from the Tbird.

Heads were pulled from a 1996 Explorer and are GT40 (non P) heads. I went with these as the GT40P heads are difficult to fit in the Maverick without cutting the shock towers. The heads were hot tanked and 0.006" removed to true up the surface. 3 bent valves and seats were replaced. New seals. Picked up an Edelbrock Performer RPM intake cheap from a friend.

What I want:
I want the car to be fun to drive, but not uncomfortable for long trips. Mostly for street use, but I’d take it to the strip once or twice a year. The car has A/C but I’m not convinced I should keep it. Needs an overhaul. Currently running manual brakes but considering installing a power brake booster that I have so I need adequate vacuum. May want to add a power adder later, but it’s not in the budget right now. I don’t want this to get too expensive so nothing outlandish.

What I need:
Basically at this point I have a bunch of stuff to purchase and I’m stuck on a few specific points before I can begin assembly. Basically, a lot of these parts depend on other choices so I don’t really know where to start.

1. Pistons
The heads have a chamber on the larger side. About 65cc. Block is stock deck height of 8.209”. I have the stock rods from the 1993 Tbird.

2. Camshaft
I have the stock roller cam from the Tbird but I’m almost certain that won’t do.

3. Rockers
Have the stock rockers and springs for the Explorer heads but they should probably be upgraded.

4. Intake/Carb
Going carbeurated for now. Have the Edelbrock Performer RPM that I picked up. Looking at something in the 600cfm range I suppose.

Although I'm not very knowledgable on this kind of thing. LMK when you need a hand with stuff. I can't do real heavy work anymore due to and injury, but can still do some wrenching. It's always good therapy, LOL. And I can clean/paint parts and get beers pretty well too...

1. you didn't mention if you had purchased pistons at the time of the block bore........You should always send the pistons to the machine shop with the block you have that you plan to bore, It is never recommended to blind bore a block to a certain spec without having the pistons there to be fitted to each cylinder.....anyway, if you want a decent piston vs price, PROBE industries sells decent bang for the buck, I just did a set up with such, with scat rods, ect ect....

2. cam??? tfs stage 1 will suit your budget

3. rockers?? since you have pedastal mount gt-40 heads, look for a set of pedastal mount roller rockers, such as FRPP'S, AND you may need to use a shim kit when installing since the heads have had machine work, to reach the proper torque on them/ preload.

4. performer rpm will work fine, I ran such on a stroked 10 sec 85 gt edl 1406/1405 will do you fine, I ran a 1405 on a 92 stock motor and ran 13.4's with it and a performer 289 intake

Unfortunately no, I do not have pistons. That's probably my biggest sticking point right now decision-wise. The machine shop never suggested getting the pistons first either...

At this point I'm looking for a machine shop around here expecting I'll need to have everything verified. Before I do that I'd like to pick out some pistons but I just don't know where to start. What static compression ratio should I shoot for?

use a flat top piston with the gt-40 heads and if you use a 9333pt1 gasket you should be around 9 to 1 but define your goal as to what you hope to do/achieve with this motor and that'll help with the parts choice as well as budget??

From what I've researched so far, the flat tops will get a Mustang GT-40 head to 9:1, but the explorer heads are 6cc bigger combustion chamber so I lose about .75 getting around 8.25:1. This is what I'm having trouble with.

Do I:
1. Shave the heads, shim the rockers, go with flat tops.
2. Get a dome piston.
3. Settle for lower static CR.

iirc a p head is 58 cc and a regular gt-40 is 64cc, with flat tops and gt-40's from the factory the mustang cobra iirc was over 9 to 1 so don't see how you come up with 8.25......my build right now has -4cc flat tops 4.030 bore and 60 cc heads and compression with a .047 gasket comes in at 9.3 to 1 with the piston .010 in the hole

The numbers I had were 59cc for the GT-40P head and 65.5cc for the Explorer GT-40 head. I measured mine at 65-65.5cc. The GT-40 heads that were factory on Mustangs were milled 0.020" to reduce chamber volume and increase compression ratio from what I've read putting them around 59cc as well. Basically the estimate of 8.25:1 that I made was calculated from 9:1 at 59cc chamber to 65cc chamber like this.

9 CR * 59cc = 531cc
65cc - 59cc = 6cc
531cc + 6cc = 537cc
537cc / 65cc = 8.26 CR
*note* this is not accurate, but ballpark. doesn't take into account gasket thickness and piston recess, etc.

When I put your numbers in the CR calculator at SummitRacing.com I get 9.27:1. If I change the chamber size only to 65.5cc it puts me at 8.7:1. I guess my question is will this CR suit my needs (basically fun street/occasional strip use) or should I make some adjustments? Also, should I go with forged or hypereutectic? What's a safe gasket thickness/brand. You mentioned the 9333pt1, but I'm not familiar with that.

These Probe pistons sound pretty close to what you're talking about and put me around 8.68:1.

These Speed Pro pistons are 8.81:1 with a 0.047" gasket and 9:1 with a 0.038" gasket.

I found these KB Pistons that are a 2.60cc dome. Putting all the numbers I know into their CR calculater, they end up 0.008" in. With a 0.038" gasket they put me at 9.64:1 and with a 0.047" gasket they are 9.48:1. They are hypereutectic pistons however.

Thank you for the input so far. I just don't want to mess this up...

dtb147 wrote:The numbers I had were 59cc for the GT-40P head and 65.5cc for the Explorer GT-40 head. I measured mine at 65-65.5cc. The GT-40 heads that were factory on Mustangs were milled 0.020" to reduce chamber volume and increase compression ratio from what I've read putting them around 59cc as well. Basically the estimate of 8.25:1 that I made was calculated from 9:1 at 59cc chamber to 65cc chamber like this.

9 CR * 59cc = 531cc
65cc - 59cc = 6cc
531cc + 6cc = 537cc
537cc / 65cc = 8.26 CR
*note* this is not accurate, but ballpark. doesn't take into account gasket thickness and piston recess, etc.

When I put your numbers in the CR calculator at SummitRacing.com I get 9.27:1. If I change the chamber size only to 65.5cc it puts me at 8.7:1. I guess my question is will this CR suit my needs (basically fun street/occasional strip use) or should I make some adjustments? Also, should I go with forged or hypereutectic? What's a safe gasket thickness/brand. You mentioned the 9333pt1, but I'm not familiar with that.

These Probe pistons sound pretty close to what you're talking about and put me around 8.68:1.

These Speed Pro pistons are 8.81:1 with a 0.047" gasket and 9:1 with a 0.038" gasket.

I found these KB Pistons that are a 2.60cc dome. Putting all the numbers I know into their CR calculater, they end up 0.008" in. With a 0.038" gasket they put me at 9.64:1 and with a 0.047" gasket they are 9.48:1. They are hypereutectic pistons however.

Thank you for the input so far. I just don't want to mess this up...

don't worry about the pistons from KB being Hyper, they can take a healthy dose of NO2, I ran them in a set up with 58cc afr heads and a 100 shot, no issues, I f you were running an aluminum head I'd say do the kb pistons but you're planning on running a cast iron head, the gt-40 heads unless worked to the max aren't gonna be a killer combo. How fast do you want the car to be??

I'm currently do a build with these and 60cc eddy rpm heads and a t-trim with 12 psi:
http://www.summitracing.com/parts/PBP-10660-030/

I do realize at this point that the money put in the GT-40 heads probably would have been better spent on some aluminum heads instead. Perhaps sticking with the flat tops even if the CR is a little low would be good so that I can change heads later if I like without having to switch them again. But I may be getting ahead of myself.

What do you mean by how fast? I've never run a 1/4 mile or anything so I'm not sure. I suppose 12s would be ok. The faster the better, but personally it's more important for it to be reliable. I'd like to see 300rwhp, but I think the heads might limit me a bit there.

the heads are your limiting factor, get a decent set of flat tops, not them cheap arse 4 valve relief, go for the 2 valve relief, you'll thank me later, when you upgrade to a 2.02 valve in an aluminum head. the 2 valve relief will accept larger valves without flycutting, you'll need to balance your rotating assembly, spend time port matching heads to intake the best you can, get some 1 5/8 long tubes, get roller rockers and matching the appropriate stall convertor and rear gears will be key along with tire size, for cam, I like going with custom cams that way the cam is taylored to my build, but that's me. I hate building combos twice when the first one underperforms but if that's what you wanna do later, so be it, use a tfs stage 1 cam in the meantime. REMEMBER to degree the cam not just install it dot to dot!!

Ok. I've been deliberating this for a few weeks and I'm considering going with a 331 stroker kit. It won't require as severe modifications to the block and keeps the pins out of the piston rings. Seems like a good choice if I don't want to have to do the bottom end over again when I upgrade the top end, but will still be relatively reliable.

I could use the heads I have for now and swap them later, or sell them and save for a set of aluminum heads. Either way I could at least start on the short block assembly. A 331 kit with flat top pistons would give me about 9.6:1 CR with the current heads and 10.4:1 with a set of 58cc aluminum heads with sounds like a good place to be either way.

I think 500hp is more than this factory block should ever see so a basic stroker kit should do. Do any of you have experience with any of the kit manufacturers? I've read a little about SCAT, Probe, and Eagle. Comments or thoughts on this route are welcome.

Do you think I'll be able to sell the stock crank/rods? What would be a reasonable price for a machined crank and rods? I still have the fuel injection setup I could get rid of as well, but as it's the smaller Tbird setup I don't think there is much demand for that.

dtb147 wrote:Ok. I've been deliberating this for a few weeks and I'm considering going with a 331 stroker kit. It won't require as severe modifications to the block and keeps the pins out of the piston rings. Seems like a good choice if I don't want to have to do the bottom end over again when I upgrade the top end, but will still be relatively reliable.

I could use the heads I have for now and swap them later, or sell them and save for a set of aluminum heads. Either way I could at least start on the short block assembly. A 331 kit with flat top pistons would give me about 9.6:1 CR with the current heads and 10.4:1 with a set of 58cc aluminum heads with sounds like a good place to be either way.

I think 500hp is more than this factory block should ever see so a basic stroker kit should do. Do any of you have experience with any of the kit manufacturers? I've read a little about SCAT, Probe, and Eagle. Comments or thoughts on this route are welcome.

Do you think I'll be able to sell the stock crank/rods? What would be a reasonable price for a machined crank and rods? I still have the fuel injection setup I could get rid of as well, but as it's the smaller Tbird setup I don't think there is much demand for that.

severe block mods for a 347??? notch the skirts, that's it..........and the ole rod rationale/pin myth rears its head again........fyi, I as well as a few of my friends run 347 with no issues, going on 4 years, only issue I have is keeping head gaskets on it......iirc a little blue bottle helps that..lol, also got a friend who uses his 95 gt with a ford racing crate short block/347 in his courier service, has 100k on it last I talked to him and you won't be anywhere near 500 hp unless you build it to turn some serious rpm, as well as some compression = more than 10.4. A recipe for such would be a solid roller set up for combo to turn at least 7k+, 205cc head , victor intake or tfr r box intake, serious exhaust a fuel system for 500 hp..ie, change pump, 36-42 lbs inj's, and the list goes, I think you'll find out and I mean no disrespect, most novice street/strip stroker enthusiests end up with a stroker that puts out 325-360 rwhp, mine ran low 11's on the motor at 120+ in a full weight 85gt, so I guess mine was in the 380-390 rwhp and on a 100 shot ran mid 10's at 128....so mine was average and this was all on a stock block, it is currently under the knife getting a new top end, IT HAD 58 CC AFR'S and will be getting some custom tfs 203cc's and a single plane intake vs previous dual plane and better exhaust,....outline your whole stroker combo and I can tell you where you may be headed

as for your other questions......skat crank and probe pistons are fine!! a kit from CHP would be your best bet........and sell the stock rotating assembly??..lol consider that stuff door stops. I run skat rods in both my 347 and s/c 306 and a skat crank in the 347 and probe pistons in both set ups, works great buy with confidence

Sorry. I'm not typing clearly because I injured my neck and I'm a little drugged up. I didn't mean to say that I thought I would end up at 500hp, what I meant was the basic kits seem to be rated up to 500hp so it doesn't seem like I need to spend the extra $$ on a 4340 crank or anything more than a basic kit like the Probe Street Fighter series kits. Or are there other reasons to upgrade to a better kit?

I was looking at kits on CHP, and I noticed that they offer balancing. Is this service worth using (I need a new harmonic balancer/flexplate/flywheel anyway) or would it be better to have it done locally? I also thought about getting it balanced with both a flexplate and a flywheel as I intend later to swap to a manual transmission. Is this something that can be done?

Stock crank will outlast a stock block, power wise... so will all the rotating assembly.

Dont use stock retainers though, when using higher lift cams, stock retainers are cast.

you can get both balanced IF you also have the pressure plate. That is where most of the inconsistency of weight is. Gains there are fairly large.

get the rotating assembly balance locally and "yes" it is a must, all probe pistons and kits come with a disclaimer on the pistons that say you must balance your rotating assembly, expecially when using a stroker kit, 28 oz balance stuff is the most common for strokers, get s stroker kit with a cast steel crank, it'll hold up fine no need for a forged crank