[charles bledsoe]

Are both #48 and #62 1969 Ram Air III heads?
Thanks.

[b-man]

Yes.

[charles bledsoe]

What is the difference between them, or is there any?
Thanks.

[77 TRASHCAN]

If speedy Bart doesn't beat me to the punch...the 16's spec @ 72 cc chambers, the 62's @ 75 cc chambers. I've been told the 62's were on cars w/ A/C. Both essentially the same performance wise. Both were the bread and butter cyl head choices, until aluminum heads "happened".

[Kenth]

#48 are RamAir III and H.O. M/T heads and #62 are H.O. A/T heads.

#48 has smaller combustion chambers and stronger valve springs without oil shields.
No RamAir heads uses oil shields AFAIK.

[steve25]

In stock form and with less than .500" of valve lift it will only be the difference in compression between the chamber size that will make for a power difference between the heads talked about here if that's what part of your question is!

[STEELCITYFIREBIRD]

Do you need a set of #48's for a correct restoration?

[b-man]

Saw a set of #62 heads on a '69 Trans Am owned by Jim Wangers some time back, it was an air-conditioned car. Can't recall if it was a stick or auto trans car.

Once owned an all original '69 400 Firebird equipped with the standard 330-HP 400 that was a 4-speed air-conditioned car, it still had the original #62 heads perched on top the original block that had the correct VIN stamped on the front near the timing cover.

So it would seem that some RAIII applications did use the #62 heads, as well as some non-RA manual-trans cars. Perhaps the fact that air-conditioning was used somehow mandated the use of the slightly lower-compression #62 heads, at least on the F-body cars.

[ponchjoe]

Originally Posted by b-man

Saw a set of #62 heads on a '69 Trans Am owned by Jim Wangers some time back, it was an air-conditioned car. Can't recall if it was a stick or auto trans car.

Once owned an all original '69 400 Firebird equipped with the standard 330-HP 400 that was a 4-speed air-conditioned car, it still had the original #62 heads perched on top the original block that had the correct VIN stamped on the front near the timing cover.

So it would seem that some RAIII applications did use the #62 heads, as well as some non-RA manual-trans cars. Perhaps the fact that air-conditioning was used somehow mandated the use of the slightly lower-compression #62 heads, at least on the F-body cars.

My numbers matching '69 Firebird 400 automatic with AC had 62s on it but it was just the standard 330 hp.

[Blackened]

So does this mean that ALL 48 heads are Ram Air IIIs?
I saw a set bolted to a 9790071 block a few days ago that a guy had for sale. From what I found while doing some research, you would have to use dished pistons (due to the small chambers) in order to run on today's fuel.
I was wondering how much that combo was worth.

Also, 12s are considered Ram Air IIIs as well for the 70s?

[b-man]

Originally Posted by Blackened

So does this mean that ALL 48 heads are Ram Air IIIs?
I saw a set bolted to a 9790071 block a few days ago that a guy had for sale. From what I found while doing some research, you would have to use dished pistons (due to the small chambers) in order to run on today's fuel.
I was wondering how much that combo was worth.

Also, 12s are considered Ram Air IIIs as well for the 70s?

Not all #48 or #12 heads were used on RAIII engines. Most of the non-RA manual-trans engines used these heads.

However most of the factory RAIII applications for '69 and '70 did use these heads.

So for the sake of identification you could say all of them were RAIII heads.

[android 211]

62s were standard 400 engine automatic transmission heads. 48s were standard engine 400 4 speed heads. Apparently if you ordered RA III you got the same heads depending on transmission. 12s were RA III '70 400 heads. 13s were standard engine 400 automatic heads. Flow on all of them was similiar with 48s very slightly the best. They varied slightly in combustion chamber size but after 45 years most have been milled.

[Kenth]

I have had several #48 and #12 matching head sets and they all had the same 66cc combustion chamber style with the small "eyebrows" at spark plugs.
Still have a set of spare #12 heads and the original heads for my 1970 Judge.

[blown 68]

and to add to this, my all original, un molested 1969 ram air III automatic car had 48 heads on it. numbers match motor, factory head gaskets still on it when i freshened it up. always thought the 48"s were 4 speed only, but not on my fremont built car.

[GOAT WHORE]

RAIII cars got 48's as well as 4spd non RAIII cars.