Need opinions for my 86 302 roller cam rebuild

I am doing a complete retro mod on a 1973 Grabber. I bought a non running car with an excellent body, a 1986 roller cam 302, T5 combo. The EFI was replaced with an Edelbrock 289 Performer intake and 600 CFM Holley and MSD distributor. My plan is turn this into a 331 stroker but that is as far as my plan goes. On the back end I plan on a 3:55 positrac in my 8 inch rear end. I'm looking for ideas for a budget top end. Don't want to spend the money on new heads. Should I keep the stock heads unmodified? I am not looking for a high RPM screamer of a drag car but don't want to be embarrassed on the street either. Compromise and budget are the key words here. Suggestions on the cam, manifold, carb, head modifications compression, valve springs, valve size etc will be greatly appreciated.

 

For a 331 you will not want the stock heads, just a waste of money IMO.

Even some Edelbrock E heads would be better, if you're on a budget you cant go wrong with these:

http://www.summitracing.com/parts/RHS-35304-01/

http://www.summitracing.com/parts/WRL-053030-1/

If you cant afford heads then give up the stroker kit in favor of the heads, you will be way happier in the long run.

 

The 86 heads are garbage, atleast swap to the 87 and newer E7 Heads. The 86 Pistons will also limit your cam choices becuase they have no valve reliefs cut into them. Most aftermarket heads with bigger valves will not work well with those pistons and a cam upgrade. If you go with the Trick Flow heads then they will clear with a B can and maybe some a little larger. The angle of the valve on the trick flow heads allows more lift before it will contact the piston.

If you are talking budget then dont use the word stroker in the same paragraph. Save the money you would think about spending on a stroker and find some used trick flow heads for 800-1000. then a Motorsport B cam. Some roller rockers, Performer RPM manifold or Air Gap, and a 600cfm carb. Should be an easy 300-325 hp.

 

i agree that your better off spending money on some nice heads and just rebuilding the 5.0 with new pistons that have valve reliefs for the bigger valves.

all a stroker does is mover the same volume of air at a little bit lower rpm. it will build a little more torque than a 302 but will make close to the same hp. afr heads have made 400hp on a stock 87-93 5.0 bottom end.

 

I am using the GT40 heads (not the GT40P ones) with very good results. 88 non-roller block converted to roller, Torker289 intake, and Holley 750 double pump carb. It is a bit too much carb for a low rpm engine, 600 should be fine for you, but I spin mine to 6500-7000 and it likes the 750 at that point.

Performer289 is not much better than stock, but made in aluminum. There are plenty of better intakes out there, but if you just want a decent little loud street screamer, you could make it work.

 

I'm with the others here, what you're attempting here isn't really feasible as far as "low buck" goes. In building a 331, all you're going to use is the bare block. But in building a 331, it's pointless to top it with those E6 heads, and it's also pointless to use that intake as well. If you want something that'll put out decent power, go find a 5.0 from an Explorer or Mountaineer, then swap out the intake for something equal to a Performer RPM or Weiand Stealth. Replace the stock rockers with Crane 1.7 Energizers, then add headers. This will give you an honest to God 275-300 hp motor that'll burn the tires off the car when backed by the T5 and 3.55's. If you cannot find an Exploder 5.0, then pull one from a 94-97 pickup or van, these will have the same shortblock, but will be topped with E7 heads, all these need to breathe is to spend 30 minutes removing the Thermactor bumps from the exhaust port roofs using a drill and a good carbide bit.

 

This is all great advice and all very logical. No chance that I will buy another engine for this project. I need to work with what I already have, Investigating heads this morning I became stuck on the Trick 170 aluminum heads. The claim is you can use stock pistons (which I will likely be replacing anyway) and a cam with as high as 0.55 all for $1100 for the pair. Am I missing something? This sounds like a nice combo. I was trying to keep my parts list under $2000 but could go a bit higher. Once I have it all figured out I'll take the parts list to my favorite machinist/engine builder and let him have a go at putting it all together for $$. You guys have been a GREAT help. Would a 670 cfm holly be to much carb, or should I stick with the 600? The Weiand Stealth combo kit for $225 sounds reasonable. Have to do some research on cams as well.

 

670 will work, but a 600cfm with everything else being equal should work better. a 302 doesnt use 600cfm untill at least 6500. so unless your building a dedicated racing motor any cfm greater than 600 is a sacrifice of low rpm performance.

 

I've got to throw another vote out there for the GT40 heads. If you're building on a budget, they'll provide significant gains over other stock heads and free up some cash for the headers, exhaust, intake, carb, cam and everything else you're going to end up buying.

In my build, ideally I would have gone with aftermarket heads, but I had so many other things to buy that it wasn't really feasible unless I wanted my car to be yard art for a few more months. I didn't, so when I built the second 351w I went from ported D2OE heads (which are actually pretty decent for an OEM head) and a Comp 268H cam, to stock GT40 heads and an XE268H cam. Everything else stayed the same between the two engines. Intake, carb, exhaust, gear, accessories, everything... Yet there was a night and day difference between them. The first 351w even had a tiny bit more compression, yet the second one pulls a good bit harder throughout the range and it revs higher. The two cams aren't that radically different so I have to attribute those gains to the heads.

 

Here we go again........................You're listening, but not hearing anything we've told you. Good luck building what you claim to want for $2000.

 

Better stick to what you know. You missed the ball completely here. Your advice here is based on the erroneous assumption that a 600 cfm carb (or any other vacuum secondary carb) supplies 600 cfm worth of air flow at all rpms. That's just not true. The difference in cfm rating between a 670 and a 600 is 35 cfms with the primary's in service. It's hardly enough to sacrifice anything on the bottomend with a 331 such as what he's proposing to build.

 

Sorry baddad but your not listening. I heard the advice and decided against going with a stroker and invest in heads, I asked about the carb because I have one on my shelf. I also have the gasket set, timing chain, sprokets etc so no investment required. Going in this direction the parts I need I can get for $2000 or a bit more plus some labor, inspection, honing etc.

I'll take a look at the GT40 heads. Havn't had time to investigate.

 

Thanks for bringing this up. I was contemplating doing the engine change, as I also have an 86 Lincoln block, and I think I will go in the direction you are, just upgrade the heads and ignition, and some new headers. Should be sufficient, without breaking the bank.

 

Hey Earl,

I put E7 heads on an '86 engine with the pistons with no valve relief cuts. Word is you get enough piston-to-valve clearance in about half of those combinations. I measured mine and the clearance was marginal but it worked fine. If your Lincoln engine has those pistons be sure to measure the valve clearance and make some cuts if necessary.

Based on advice here, it sounded like GT40 heads would NOT work with those pistons.

Jim

 

Part numbers. I pulled the heads off of what is supposd to be a 86 302. The head number type is 7F23 and the pistons are E7ZE6110-CA. The bore is 4.00, consistent with a stock 302 bore. Can anyone tell me aything definate about these part numbers. Do they belong to a stock 1986 motor? Thanx in advance.