[napster]

I purchased #48 Heads back in 2010 from a member on this board back in 2010. My intension was to use them on my 1969 GTO once I got the engine rebuilt. I knew the original head were really beat up from detonation, so I wanted better heads as replacement.

Well, a lot of time gone by and only now am I getting the engine rebuilt. I am not using the 48 heads since I purchased some RA II heads That will go on the rebuilt engine.

What are a good set of 48 heads going for these days?

Thanks in advance.

[tom s]

Bare set on ebay for $700 OBO.Tom

[67Fbird]

aren't 48 the same as a 62

[Half-Inch Stud]

I have a set of nice 48s ready to go for $1000.

Clean, Rebuilt, tall-ported, the wider angle keepers, New GTO Chrome Valvecovers with thick gaskets. No rockers though (extra)

If these sell then my Spare 455+030 shortblock also is avail.

[tom s]

They are the same UNLESS you need 48s.Tom

[74Grandville]

48's have a 350 chamber, 62 has a 400 chamber. this can be seen when placing a gasket on them.

[Brianbigoats]

I sold a set for 700 a few months ago

[Kenth]

Originally Posted by 74Grandville

48's have a 350 chamber, 62 has a 400 chamber. this can be seen when placing a gasket on them.

Lots of 48´s on RAIII and M/T 400 engines.
And, on 350 H.O. engines as well.

Same 66-68 cc chambers as 1970 #12 heads.

[Kenth]

Originally Posted by 67Fbird

aren't 48 the same as a 62

Nope.

[Formulabruce]

Originally Posted by Kenth

Same 66-68 cc chambers as 1970 #12 heads.

Have cc'd a few sets of #12 heads, seems they were 72 cc on average...

[tom s]

My 48s are 72CCs.Tom

[Kenth]

Adding pictures of #16 H.O. heads and #48 and #12, all said to be 72 cc.
Which of course is not the case, plain to see by just a look.

If anyone has pictures of two differently factory machined #48 heads, one 72 cc and one 66 cc i would certainly would like to see those.

And, adding an excerpt from the 1970 performance catalog.

[25stevem]

A drop from near 76 CCs to just over 66 CCs makes for a much greater compression increase then a 1/4 point!

[mysticmissle]

Originally Posted by Kenth

Adding pictures of #16 H.O. heads and #48 and #12, all said to be 72 cc.
Which of course is not the case, plain to see by just a look.

If anyone has pictures of two differently factory machined #48 heads, one 72 cc and one 66 cc i would certainly would like to see those.

And, adding an excerpt from the 1970 performance catalog.

I see some machining differences, but can you cc all o f them? even if its a rough estimate?

[tom s]

Im building another engine right now with stock 48s and the chambers are 69 CCs.Tom

[Half-Inch Stud]

Kenth, those 16 chamber scallops look non-stock to me. I've owned the (good) 16s from 1968 and they had chambers like a 48 & 12.

I've seen the (nosogood) 16s from 68 with the Cast AIR injet ridge (like 670s have), and they too had the good chambers.

ah geez my 48s chambers measured 78c: with ferrea valves and chambers modified (unshrouded intake and exhaust, scallop subdued on intake and exhaust, and squish end smoothed at exhaust valve)

[SD455DJ]

For what it's worth, we cc'd the combustion chambers on a #12 head (looks like it had one .010" cut in its life) and a truly never cut #216 casting date H157 (from a 1968 428HO/M21 Catalina) which became just #16 later in the year. The #12 measured 68.6 cc's and the #216 (aka #16) at 74.8 cc's. I imagine the #12 head started out closer to 70+ cc's originally.

[android 211]

The application for 48s is 4 speed and Ram Air III. Also 350 4bbl HO. 62s go on standard 350 hp automatic 400s and Grand Prix with 400 or 428 automatic.
Pontiac made over 50,000 automatic GTOs in 69 with the standard engine, far fewer 4 speed cars.

[25stevem]

If I am not mistaken the only time a 48 casting was used along with a auto trans was with the 69 350 HO motor .
All other 400 4 bbl motors that where not RAIII 4 speed cars Got the 16 casting in the GTO and the GP, and all other 400 motors with a 4 bbl got the 62 casting.

[Bruce Meyer]

Originally Posted by 25stevem

If I am not mistaken the only time a 48 casting was used along with a auto trans was with the 69 350 HO motor .
All other 400 motors that where not RAIII 4 speed cars Got the 16 casting.

Not exactly. 69 4 speed cars got the 48,s even without ram air. The 16 casting is a 68 casting. In 69 all the base automatic cars got 62 heads.