Which alum heads for 11:1, 89 5.0 HO

[OX1]

To run on propane. Which alum heads could I just plop on an 89 HO shortblock and get that kind of compression increase??

 

[Broncobowsher]

Stock is something about 64cc and 9:1
It would take about 50cc chambers to get 11:1, outside some unfinished yates heads that doesn't exist.
Go shopping for the smallest chamber heads and pick up a set of the thinist Cometic gaskets to get the compression up that high.

 

[Okiebronc]

About the best way to go for a sbf is the AFR 165. You can get a 58 cc chamber but it will only get you to about 9.7:1. Your going to have to change pistons or do some serious milling to get to 11:1

 

[OX1]

OK thanks, will have to wait for a complete rebuild someday then. Have the entire rig to build first.........

 

[ricky]

if you can find the older style motorsport J302 heads,they were 58cc out of the box

 

[minimatt]

I do not think it can be done without piston-to-valve interference. The smallest chamber I know of in aluminum is the 58cc as mentioned by others (also the World Products Windsor Jr. Lites). They work without notching the pistons, but don't even get you to 10:1.