72ls5fla

Hey All ...

Does anyone know what the CC size is on a stock 72' 454 head?

Also, if I kick the compression ratio from 8.5 to 10.75 - 11.00 how much gain in HP could I expect to see. I figured it to be the same as a 70' LS5 which had 390 HP.

Any info is appreciated.


Bill

BigBlockk

My '70 has 101cc "290" heads. I believe the '72's had 105cc heads.

Your engine isn't that far behind the '70 LS-5. You need to remember by this time they were using net hp instead of gross.

To get to 11/1 compression you will need to change pistons. This means a complete rebuild. You can do the same thing with a street port job on the heads and a set of headers. This will have you up over 400 hp and is a lot less expensive.

BigBlockk

Later.....

72ls5fla

Thanks for the info ...

The reason I was think along the 11:1 line for compression ratio is that I am going to pull the engine anyways.

I am doing a frame-on restoration and removing the engine/tranny to do cleanup in the engine compartment/frame. I though that since I had it out I would change rear main seal, oil pan gasket (slight leaks) etc.
While I was in there do a replace of main/rod bearings for the heck of it;
the car oly has 55K miles but I like to be sure it is good for another 55K.
I want to give the engine and bell housing a fresh orange painting.

Thanks for the info on the CC size. I will order standard bore pistons domed accorindgly to get me 11:1. I was going to have the heads ported and matched to the intake.

Seems that I may actualy get more in the gross 425 HP range then ..



Bill

BigBlockk

I got some more info on this. The head should be #3999241 and the volume is 113cc. Hope this helps.

BigBlockk

Later.....

early shark

1972 LS-5 heads had CC of 113.060 to be exact.

72ls5fla

Thanks for all the great info.

I am so thankfull this forum!

Bill