I know these are crappy heads but I think this casting number needs to be rechecked. I think I have and heard of others discovering this casting number associated with a high performance heavy duty casting. Even Lingenfelter discusses these heads in some of his books. I believe I ran across one of these heads once.

I even found them in a GM parts catalog and Gmpartsdirect still sells them for $295 part #464045.

http://www.s-series.org/htm/tech/GMP...ts/046-050.pdf

 

462624.....75-86...350/400......76cc chamber, 1.72/1.5, 1.94/1.5 or 2.02/1.6 valves


being a 76cc head its not going to have a high compression ratio but it was available with the 2.02/1.6 valves which isnt too bad.

if youve got the larger valves i would mill those heads down to raise the compression ratio up and port them. with all that done i dont see why they would be a bad head.

 

I dont want to confuse these with the thin casting production heads is all. I even found some info on older casting with this same casting number.

 

If you want some heavy duty castings that aren't going to be cracked, look for some 997 castings. Normally these can be found in 350 Targetmaster replacement engines. They'll have 1.94/1.50 valves which can easily be changed to larger valves. They'll have 76cc chambers. The larger chanbers are normally refered to as smog heads but they also unshroud the valves allowing better air flow into the cylinders. Milling the heads or using dome pistons can bring compression ratios up to whatever you want.

Before you start modifying any factory heads for performance, compare prices for any good aftermarket performance head. By the time you have larger valves installed, larger spring pockets for bigger springs cut, rocker stud bosses machined for positive lock seals, valve stems cut down for higher lift cams, port work etc, it can be cheaper to install some aftermarket, out of the box, heads which will have even better castings plus have all that work already done to them.

The days of searching junk yards for factory performance parts is long gone. The aftermarket products available now are far superior.

 

Thing is I see heads like this pop up on ebay for practically nothing. I have crappy heads now but probably invest into somethning better at some point. Im kinda kicking myself because i think I tossed one of those heads once and they had 2.02 1.6 valves in them and were not a thin casting. I just always hear people say that casting number is crap whithout investigating it further.

 

Yes there is a service head that has the same casting number as the typical crappy production 624's.
It is a heavy duty non scolloped casting simular to 441's, 920
487 and 336 used on late LT1's and Z28's after '71
it is a decent head. It is not at all like the typical 624's you're likely to find in the wreckers.
Was only sold over the counter so you're not likely run into it.
See the pics

 

Production "lightweight"crap 624's worst than 882's

 

hmm I must have gotten lucky then.

 

may have been an old Mercury Marine head from a "Mercruiser" Motor.

 

Dont the lightweights have those dents over the exhaust ports or is that common? Reason i say I have seen this casting number more than once on ebay that didnt look like thin castings.

 

See look here. Are these thin castings? They dont look like the description of the crappy heads you posted. Unless the photo in the acution is innacurate representation. Im still waiting for a reply from the seller.

http://cgi.ebay.com/ebaymotors/Chevy...spagenameZWDVW

 

The seller tells ya in the discription that the picture is not a picture of 624 castings.

In the discription, the seller states that they are infact a pic of 882 castings. they are not either.

The pic is a pic of a high perf casting like a 041 186 or 462
Look at the combustion chamber.

 

Ok then thats probably what i seen then. That auction was revised today the time stamp is Sep-13-05 10:50:34 PDT. It must be an auction gimmick. Kind of misleading.

 

Ok lets try this again. I e-mailed to find out if these are the heads in the photo. To me this casting looks different than most 624s I have seen.

http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMEWA%3AIT

 

You seem hell bent on buying a crappy set of low perf heads.

Sellers on ebay like this one, love guys like you.

Look at the other set of heads listedthere. Supposed to be 991's
They are in fact a picture of cast LT1 heads (caprice)

Take that as a hint. non of the pics match the claimed casting number.

Guy's like the seller know the good desirable castings. they don;t sell them for $200. They sell off all the low perf heads to guys like you that don't know what you should be looking for.

 

Do you see me buying them. NO. But fine Ill leave it alone if that makes you happy. I guess Lingenfelter was off his rocker.

 

I think it is actually a 601 or 081 305 head. Notice the smallish 1.84" intake valve and the way the intake valve is shrouded by the chamber. Then also notice it has an older style performance chamber but it is reduced in size. I believe it to be a 53cc 601 head with 1.84" intake and 1.50" exhaust valves.

 

My next heads will most likely be sportmans IIs or something but I like to investigate crap like this. I hear these things that builders say and wonder if they hold water.

 

My new 383 is going to use Dart Iron Eagle 230ccs. 2.08" intake valve, 1.50" exhaust, 72cc chamber, screw in studs, guideplates, roller cam springs, etc.

 

I would really like some aluminum Darts but then see the cheaper knockoffs on ebay. The Darts are like in the $1,000 while the knockoffs are like $750. I wonder if they use a lower grade of aluminum. because I want them to last.