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ProComp BBC Heads

101K views 36 replies 26 participants last post by  Busted Knuckles 
#1 ·
Hi,
I realize this subject comes up on other forums but I wanted to check here too. I recently picked up a 496 BBC with ProComp aluminum rect heads. It has a mild .650 lift hyd. roller and 10.1 comp. The short block has all good stuff, no questions there. Dynoed at 630 hp @ 5700 rpm. I'm not looking for any more HP, just reliability as this is a bracket-index type car. My tuneup is a bottle of shoe polish, if you know what I mean. Has anybody has any REAL problems with out of the box ProComp heads? I have heard everthing from 9 second ET's out of the box to "major surgery" required. Can somebody give me real life examples who are using them now? Thanks in advance!!
 
#3 ·
Do a close inspection of pushrod to rocker to valve tip geometry.Mine were way off.Had to modify guide plates to correct.I believe another auminum head big name also mentions this and to use their plates for correct geometry.As for my experience so far,i've had good luck.I have nothing to compare to though because i assembled with these heads.As far as reliability,1 1/2 years of street driving with some 1/8 mile drag racing and no problems-----so far.As for performance,my car is a 67 chevelle street car,461 cubes,4000 converter,turbo 350,4.10 gears,3 inch exhaust,single plane intake,950 proform carb,255/607/108 bullet solid lift cam,10.5-1 compression and with 28x9 slicks it runs 7.00s@98mph with a 1.56 60 ft. time.Hope that helps.
 
#5 · (Edited)
You have a very similar setup to what I have.... I was hoping for some 6.8 or so out of mine so it looks like I will be in the ball park. Mine is a 468 with the Pro Comp 320 heads, Manley valves and Isky springs, 10.5:1 speed pro pistons, Crower 252/262 @.050 .607/.620 lift on a 108CL, Holley strip Dominator intake, Holley 850DP, TH400 with a 4500 nitrous converter, 4:10 gears and 29.5X10.5 slicks. I also have a 275 shot on top just to move things along...lol.

As for any problems with the heads on assembley I have had no problems at all. I bought them assembled (minus the rocker studs and guide plates which I just used the ones out of my stock heads). The only 2 things I have had any issues with is getting the correct head studs for the heads and custom pushrods. Not that either is any big deal they are just differant than normal. When I ordered the head studs I was told that they were for these heads and they had 4 differant length studs. I needed the set that had only 3 differant lengths. So I ended up using 4 of my old head studs and all is well. As for the pushrods the long ones are your standard +.100 pushrod (9.350) but the short ones came out to be +.270 (8.550) But you can get them from Trickflow at a reasonable price. Other than that everything has gone well with the assembly. I have not encountered any of the "horror" stories that you keep seeing around. I know already that they do not flow anywhere near what they advertise but that is no big suprise. From the flow numbers I have found from reputable machine shops that have posted them they actually flow around 330 on the intake and 230 on the exhaust which is not bad at all. Pluse you lose and extra 100 pounds off the front of the car which is never a bad thing.

Hear are a few pics of my heads and them on the motor.




















On a side note I am runing an oval port intake with these heads. I tried cheap felpro oval port intake gasket on them and the port stuck out over the top of the gasket but with an Ultra seal large oval port intake gasket it all works nicley. My intake is also ported to that intake gasket so it all works out well. You can see in one of the pics how the ports line up.

Sorry for such a long post but I thought I would give a little detail since I never could find and worthwhile info when I was searching for information on these heads.
 
#6 ·
I have them on my 69 chevelle and so far no problems.I run a 468 with 10.3 actual compression and a bullet 580 lift 255/265 at .050 camshaft.The geometry isnt dead on and you will probably have to work on the intake ports to get your intake to fit properly.I used a square port intake and it took alittle work to get the ports even close.I bought my pushrods from trend after measuring for the right length.This is a situation of getting what you pay for.I have heard the horror stories about these heads but so far in my situation and a few others they are working fine.If you have a unlimited buget then buy the the 2500-3500 afrs.When I bought mine I got them to my door complete for 950.00 brand new.I wanted to try them for that price.Good luck
 
#7 ·
That is pretty much the same reason I got them.... I am not made of money. It was still hard to come up with $1,000 for a set of heads but I was able to do it. But there is no way I would be able to come up with $2,500 - $3,500 for a "good" set of heads unless I sold a car to do it...lol.
 
#10 ·
DId you look at patriot heads Gunner is the owner and he is here on team chevelle I have herd both good and bad about them but I spoke with gunner about a set of both sbc for my 350 and a set of bbc heads for my 468 his prices are great for a complete head. here is a link.
https://www.patriot-performance.com/xcart/product.php?productid=15&cat=33&page=1
you can find him here under Gunner. might wanna look him up.
just my 2 cents.
 
#8 ·
There are plenty of cars running damn well with them. I think the key is to have them checked and prepped by a respected shop prior to installation. Many buy them unassembled and have there machinist assemble them with good parts. I know of a set that is running 8's with N2O.
 
#9 ·
When they say the geometry is off, do they mean b/c of the guideplates? If so, that's not a big deal. I've had a set of Edelbrock heads and AFR heads that needed work with the guideplates. Now, if the rocker stud is not where it needs to be vs. the valve tip, or vice versa, now we have a major problem.
 
#11 ·
I read a thread on hear where he was talking about his heads and the Pro Comp heads and the differances between them. I looked at them also but they were just a little out of my price range. But if I had the time to save up a little extra money I probably would have gone that rout. I have a friend that has a set of the Patriot heads on his small block Corvette.
 
#12 ·
well call him and let him know what your budget is he is a very nice guy and he mey be able to help. I told him how much I had to spend on the sbc heads and he really helped me out. And if memory serves he gives discounts to TC members but dont qoute me on that as Iam not totally sure you will just have to ask him.:thumbsup:
 
#14 ·
AHH good point guess I should have asked if you had already bought the Procomps. live and learn then get loves I guess:D
I just dont like procomp parts reasons are too much to get into suffice to say they have cost me way more then I eversaved by getting them:( nuff said about that. hope they work great for you.
Jeff
 
#16 ·
I have had the rockers on my heads already to check the pushrod length and mine lined up great. Also, I did not get these heads assembeled by Pro Comp. I bought them from a place in New York that assembeled them with Manley valves and Isky springs. Everything has looked great with these heads so far.
 
#18 ·
Camarotypelt, I just bought a set and they might be from the same place you got yours. They have all good parts. Do you have the specs on your springs?

Also,my part number says pc3010 not pc3021. Know the difference?
 
#20 ·
I have a '70 El Camino with a 6-71 blower and formerly ran aluminum GM Performance rectangle ports. I used these heads for about 7 years without a hitch. I recently went to the machine shop to freshen up the heads and they told me that several of the guides were worn and the bill would be in the $700 range. I looked for some alternatives and found Pro Comp. I did check out several forums to see if there were any reported issues but the only negative things I saw were minor appearance issues or Australian/Chinese bashing which is not issue specific. Well, I have an issue specific complaint that you had better read. After installing the same type valve/spring combo that worked flawlessly on the GM Performance heads I took the car out for it's test drive. About 10 min. in town and then mild acceleration (no more than 3300 rpm) to get to freeway speed and then cruise at 3000 rpm for about 5 miles to get back to my off ramp. By the time I reached my off ramp I started hearing what sounded like mild knocking. Engine rpm at this point is about 1800 rpm. Checked oil pressure and that was at 64 psi. I then went to shut off the engine but before I could there was some really bad rattling and then the engine stopped. We all know it's NEVER good when that happens. Removed the heads and discovered that every single piston had come in contact with the valves and the number two intake valve was actually snapped off and ended up in the number 6 intake port. I have tried two progressively stouter valve and spring combinations with EXACTLY the same result. I won't even tell you about my Pro Comp distributor nightmare but that piece of crap ended up in the trash. I hope my experience helps others not to buy Pro Comp because my experience with both heads and distributors has been a very, very bad one :mad:
 
#25 ·
Thats the general concensus ^ ...I know of some similar people who did the same thing by not checking the pushrod lenghts. Diffrent manufacturers = diffrent product even though there identical to another manufacturer.

All heads that I have ever bought went straight to a headshop
 
#22 ·
Ive built 2 BBCs with pro comp heads...both 10:1, hyd. cammed 461s, one oval, one rectangle. the oval motor tested fair for a puny cam, carb and intake. the rectangle motor was a low budget slap together with a .590 hyd. f.t. cam, team g and pro systems 850.....it went low 7s in a 4400lb street truck and a pretty big fella behind the wheel.
the ports were left alone and they didnt flow bad out of the box. a little smoothing of the rough edges would probably really help these things.
they did need a lot of port matching work on the intake side...especially the rectangles.....took nearly 1/4" out of the roof to match to a standard BBC gasket.
and as rats4ever said...rocker tip to valve tip was a big issue and needed to slot the guideplates to straighten them out.....some rockers were 2/3 off the valve tip!
 
#30 ·
Posting an update for you guys FWIW:
The owner of the rectangle port motor above bought the heads complete from another individual. We threw the springs, locks and retainers away, but I could not convince him to toss the valves and run a big name quality piece, since his were brand new. He understood the damages a dropped valve will cause and that there was no warranty if it did, but despite constant warnings, he could not justify 300.00 for different valves when his were new, and rolled the dice.
Fast forward to this fall, one year and 5k miles later- its back in the shop with an intake valve head off, broke piston, cracked cylinder, and trashed head, at least beyond the cost of a new casting to repair the old. There was NO sign of any piston to valve contact, sticky guide issue, etc........cant tell if they are a 2 piece valve or not, but its a clean break.
Can the part be blamed? Dunno....but he regrets not listening to me now.
Please, PLEASE, dont take any chances!!! you get what you pay for, fellas- if youre going to run a 1000.00 set of aluminum heads, at the very least order them bare, and load them with good parts (like was done on the oval port motor above)- especially on a somewhat healthy motor!!
 
#23 ·
I'm using a pair of the 3021 heads. I purchased Trick Flow pushrods and Dart adjustable guideplates, and .250 taller rocker studs(Brodix). I did a test pattern for the rocker tip contact on the valve stems. No interference on the spring retainers to rocker arm. To check for pushrod required length, I made my own set of adjustable pushrods from a pair of stock rods, cut and drilled and tapped. I used P to V checking springs. Did a port match for the 1275 gaskets to a Brodix HVH2016 intake. I did however have to trim a few of the guideplates to clear access for a socket/headbolt. I think its all in the careful preparation and clearance checks needed during installation that make or break these heads. Any cylinderhead for that matter. I wouldn't trust any of the brands. Piece of mind and knowing what you have once its all buttoned up.
 
#24 ·
i have a set i bought from dougherbert they were assembled with better parts also. i drag race mines and have had no problems . they used adjutable guide plates and comp retaners and locks i also used trikflow pushrods did notice a slight rocker to push rod misalignment but notting major and i do spray a 200 shot of nitrous .also the part # is 3021 i think they are newer castings
 
#29 ·
A hammer and a block of wood.Thought the same about rockers but all on the exhaust valves only.I assume the studs not square to the deck.1200 miles and lots of beatings on that thing but as Willy says "your always on my mind" the AFR 315 will be on it by time the grass is showing up here in the "great white north"
 
#31 ·
I got mine from a company that sells them under the name strikeforce. They get the bare casting and assemble them. I put mine on a driver and the only problems I ran into was having to get custom pushrods and cutting and welding the guide plates. Cake really and the geometry looks great. I'm not going for all out performance and couldn't pass up the price. I would love to have a set of brodix or AFR's but they were not in the cards after dropping a valve in my fresh 049's.
 
#32 ·
save a little now pay alot later. im kinda in the same boat iv spent alot on 4340 rods and crank mahle pistons and set aside enough for a roller cam and rockers. now im in search of heads but man they arnt giving away thos bbc heads lol. i found an awsome price on brodix rr from shannons engines in mn.
 
#33 ·
i bought a set of the cast bbc procomp heads and did some mild porting. ported me intake holley strip dominator. bolted them on to my 498 bbc with a 600 solid lift cam. the engine is 9 to 1 compression. went 10.00s first weekend out. in 2800 lbs racecar. the quality of the casting seem good. i also had a machine shop inspect them before i assembled them. I heard the tricks is to buy them machined bare and buy valves separate .
 
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