I have the opportunity to get a documented 1972 47k 455 frrom a recently wrecked car. The 455 runs great and is COMPLETELY stock, I believe it has C heads on it. I would run the engine with no modifications except possibly an ungraded cam since it is a great runner and at a great price. Wanted to get input on just installing some ported/milled 70 cc E heads on it that are available for purchase or aluminum heads with just a cam upgrade.

Most of the 455s I see discussed with milled & ported BB or aluminum heads have been rebuilt with different specs than bone stock. I don't never see anyone installing such heads on low mileage stock 455s. I am figuring at worse case scenerio, I would have to get intake to match the milled heads but is there any other issues that hinder this from happening?

Is anyone running a stock 455 w/ aluminum or milled heads? What are your current specs with the heads? What would be the power/torque gains or guestimates from stock specs if this idea is feasible? Is 425hp obtainable from a stock 455 with milled/ported heads? I don't believe compression ratio with the stock pistons and milled heads will be extremely high?

 

Ask why a 1972 low mi engine has C heads instead of Ga.

 

The heads on it may be Ga. I'm not 100% sure

 

The stock heads are perfectly fine for low compression and stock cams. There's absolutely no need to spend the money on new heads unless the ones on the engine are crack or severely damaged.
For me, I consider aftermarket heads when compression gets above 9.5:1 on pump gas and the cam gets in the 230+ degree duration at 0.050" range. Those heads flow much better and resist detonation. Neither of those are even remote concerns with the stock cams.
IOW, there's little point to throwing lots of money at the heads on a stock short block.

 

I will upgrade cam with a head swap. The heads I'm looking at are heavily ported and milled which will increase power. I'm looking to see if anyone has swapped stock heads to milled/ported or aluminum heads onto a stock 455 & see if it is a decent idea. The engine doesn't need a rebuild. I'm trying to wake it up with head swap.

 

You may get a nice compression bump with those heads. I have a set of G heads that measured 84cc, so if yours are in that size range, then swapping to 70cc heads with thin head gaskets will give nearly a full point bump in compression. That shoulp help with your new cam.