Ok. I have GA heads on my '72. 455. I'm debating having them machined and new valves and seats. The other option is to upgrade to procomps. Everything else is basically stock. Carb, intake, and exhaust manifolds. Here's the question. Will I notice a major difference with the upgraded heads? I know they are lighter. Cost to machine the old compared to installing new is not too far apart.

 

What vehicle is the motor in and how original is the car now.
Sometimes keeping the car as stock as possible is the best and sometimes it doesn't really matter.

 

1972. 442. Heavily documented. The car is origional. No upgrades that I can find. I believe it was revalved at one point. Because the valve stems are too long creating a popping from the exhaust. Hence the reason I am pulling the heads and having them machined and redone. If I gain a lot more power from new heads I don't mind going that route also. Just not sure if I'll notice a major difference. I won't know if the heads were already ported larger until they get inspected.

 

I wouldn't change heads on a heavy documented car.I would leave it the way it came out factory. Get you GA heads looked at and get cost estimate.JMO

 

Good advice. Appreciated.

 

Don't have advice on the performance stuff although I suspect you'd need to do more than just bolt different heads on to get any big performance gain (cam also maybe?).

That being said, you won't hurt the value of the car by doing that.

Just keep the originals as they can always be put back on.

 

I would go Procomps if you are looking for better performance. Isn't the 72 442 motor like 8 to 1 compression? Get a set milled to say 70cc and get the aftermarket intake of your choice milled to match the heads. Also a better cam and and new timing set that should be done anyways. Cutlassefi, Mark Remmel can help you on all accounts. As said bag up your GA heads and keep them safe.

 

Keep it original. IMO

 

71-72 455s are 8.5:1 compression. If I recall correctly the lower compression as compared to 1970 & earlier was achieved by utilizing dished pistons not by a large chamber head.


A well prepped set of Ga heads with a carefully selected cam & a performer intake will wake that engine up.

 

Why would he want to do that? The op didn't ask for anything except if he did a head change advice. This is a heavy documented 442 why change a numbers matching car into a not numbers matching. Having the heads checked and if they need rework would be keeping the car numbers matching.

 

I am confused. Ga heads are original & I am in favor of keeping the Ga heads. Simply mill & port them & slip in a modern cam grind. That does not affect #s matching status in any way, shape or form. Please explain how my recommendations alters the car from numbers matching.


The heavy stock intake can stay if so desired to keep stock appearance but there is 25 hp in a performer intake and some weight savings.

 

Re-read what the op asked for. Did he say intake swap? Did the op say cam change? He was asking about heads only on a numbers matching 442 car. That was made clear many times.I gave my opinion.

 

Agreed. My comments about a cam swap & an intake swap are outside the realm of his post. However they are still valid suggestions for making more power while if he is going to swap or do head work.


However my comments on milling and porting the heads for more compression and better flow are valid and do NOT affect its numbers matching status as you want to imply.