It costs quite a bit to have a machine shop rebuild old heads and that's a plain waste of money. Better to just get some decent modern aluminum ones like Profilers, and with pistons to give desired final compression ratio. Profilers come in 65cc, 70cc, 76 cc. Pistons come in dished and flat top versions with stock compression height, rebuilder (low compression height), and custom compression heights (+0.010 tall=Skip White). Depending on the final deck height of your block, just pick a combo that gives you the CR that you want with a 0.041 thick Felpro 1003 gasket and 0.040 quench height from head to piston. 0.040 quench requires pistons that come up exactly to the deck height of the block and will depend on final deck height after machining (if any). If you want torque, do a 383 kit - but I'd go with a 750 vac secondary if you increase the displacement.

I happen to like your cam choice. I run flat tappet cams and have had no problem (I used to have an XE274H), but I take all precautions during initial break-in including covering lifters/cam with Joe Gibbs assambly grease, removing my inner valve springs (not the dampeners), and using 30W Lucas break-in oil. Then it's Brad Penn 10W30 (Hi ZDDP) for the rest of the engine life. I'm sure others will suggest what they have successfully used, but that's what I do and it certainly works for me. Make sure if you buy heads that they have appropriate valve springs for flat tappet cam. If the valve springs are set up for roller cam (stronger), you will certainly eat flat tappet lifters and cam lobes. I think this is a mistake that a lot of people make when buying heads off the shelf these days.

Good luck and best wishes for a successful rebuild.

 

The heads that are on it are the 3973487X heads

I believe those 487 heads are the ones that are in high demand from factory stock circle track racers. At least around these parts (Oklahoma, Texas, Louisiana) the rules are very restrictive and those are the heads everybody wants... which means they are often hard to find. You could probably get several hundred bucks for them. I had a set a while ago and sold them for $300. I used the factory stock Facebook groups to post them.

Good luck!

 

I agree, the cost of rebuildng tired old stock iron heads for the SBC has now gotten to the point you can either get modern aftermarket budget category aluminum heads for the same money, or nearly so and they will also out-perform the stock junk.....you can get into solidly made budget aluminum heads for between $650 and $850-900 depending on brand and whether bought bare w/parts or fully assembled.
A basic rebuild of stock head castings can easily top $500 in a heartbeat....Clean, magnaflux for cracks, new valveguides(nearly a given they will be shot), valve job(a given), springs(a given), seals, mill for flat deck surface....and that doesn't include new valves if the stems are scored or worn.

Sell the 487X's to a circle track racer whose bass-ackwards rules makers mandate use of stock head castings(common deal, country -wide, it is supposed to keep costs down LOL). The 487X is one of the castings they look for, as the "X" denotes a slightly larger intake port than the common 487 and other smogger-era open chamber heads like it.

 

Thanks for the sound advice gents. New heads feels like the right call. We probably should go with a stroker - think I just don't like the idea of the kid's engine being cooler than the 350 in my Camaro! This may be a stupid question, but how does going from a 350 to a 383 impact heads and cam? I understand the bigger carb, but would I need bigger heads (180CC+)? What about the cam? Would that 050 duration of 212-218 be suitable or does more displacement "need" more duration?

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Generally speaking
180CC for 350 on street
195cc for 383 on street
Few heads are equal in flow to each other based on runner size.
An XE268H is plenty of duration for a streeter 383 in a heavy vehicle.
Actually it's overlap - the bigger cube engine likes a tighter LSA but few pay attention to that way of increasing overlap (they just stuff in a cam with same LSA and more duration).
383 with good heads, XE268H, 10.3:1 CR, dual plane intake like a Performer, 1 3/4" long tube headers on pump premium and you can bet somewhere around 425-450hp at the flywheel (possibly more) after tuning and VERY streetable. A tried and true combo. The variable is how good of heads you buy, and how well they work with that particular cam.

 

Thanks Blazer!


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Here's some interesting info from a custom cam designer (from this forum). Semi custom SBC cams based on stroke and heads used. Yes they are all roller cams but you can get the idea that slightly different cams work best with different heads and strokes.

Straub Cams

I'm from the buy the best heads you can afford camp. Ended up with AFR195s on my 383. Better flowing heads needs less cam to do the same thing. Now I wish I had originally gone for AFR 210s but it has turned into a race-only vehicle and now has a solid flat tappet Crower cam with a quite tight LSA (big on midrange but no power down low and horrible idle). I'm to the point where my horsepower is getting limited by my AFR195 heads. But that's really only going to happen above 6500rpm in a 383.

Another revealing read is Vizard's How to Build Max-Performance Chevy Small Blocks on a Budget. He is big on selecting correct LSA for the engine (but doesn't differentiate between heads). Then you select appropriate overlap for your use and see what duration camshaft gives you that. He also has tables of recommended custom camshafts (which happen to include flat tappets).

 

Comp XE268 is 224/230 @ 0.050 (not what you said). LSA is 110. Vizard would use a 106LSA in a 383. Straub would use a 108 LSA in a 383. Wide LSA makes smoother idle and moves the torque curve upwards in RPM at the expense of mid-range. Smaller engines use wider LSAs.

 

Thanks for all the additional info. Yeah - I was originally talking about the XE256 when it was moderate and potentially using decent stock heads. I have AFR 180's and a XE274HR in the 350 in my 69 Camaro and like the combo. Just not sure I want to commit the $$$ to doing a stroker right. Although with the engine torn apart already, I've already committed to a decent amount of $$.

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You'll find that by the time you pay to bore the block, grind the stock crank, and resize the stock rods along with the magnaflux for cracks and new rod bolts...you know, the basic correct rebuild machining....that you could have bought a stroker kit with all new parts for the same (or very close to it)money you'll have tied up in stock parts with several million duty cycles already on them.

I don't know machine shop costs where you live, but in my area the rod resize with new ARP bolts will set you back close to $250+, and the crank regrind is an easy $200, and since you are buying pistons, rings, bearings any way once you figure the total it makes sense.
$250 rods, $240 crank regrind and mag, pistons $400+, rings $50+, bearings $50....so $1000 minimum. You can get a nice Scat crank and rods, forged piston stroker kit for $1200....and it includes rings, bearings, new harmonic damper and new flexplate.

383 STROKER ASSEMBLY SCAT CRANK 6" RODS WISECO -12cc Dh 030 PISTONS 2PC RMS | Skip White Performance - We have the best prices you will ever find for aluminum heads, rotating assemblies and strokers

 

If you're paying for it, give the kid the 350 and build the 383 for your Camaro! They are in another realm for torquey power! Plus you can get away with a lot stouter cam in a light vehicle like a Camaro.

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Ha! I was just working through that idea - building the 383 for my Camaro. Thats more engine than he needs anyways. Then I can go back to that moderate 350 build idea for his truck. I would want to keep my XE276HR cam, lifters and roller rockers though. Seems like that would work in the 383. Its a retrofit cam already. What about the AFR 180's? I kind of want to just put them on the 383 for now and get him some cheaper alum heads. I know you recommend 195 or above but I did read something saying 180 might be enough for 383 on the street. It's really just for stoplight to stoplight. It's a convertible so I never race it. Am I way off on the AFR 180's on the 383 just to save $500-600?

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Certainly the cam is fine. But the 180 heads are just not right for the 383. You may need different chamber size for optimal CR anyways. Its different with bigger cubes.

Why not leave the 180 heads on the 350 and go with some 195 Profilers on the 383. They come with 65cc, 70cc, or 76cc chambers. One is going to be perfect with the Skip White flat top piston rotating assembly.

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Good point.

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