Hoping to pick some ones brain. I recently bought a 62 sport fury, was a 361 auto car. Engine was gone. I bought a 59 New Yorker with a rebuilt 413. I have changed the crank to the 6 bolt. The engine is supposed to be 10-1 350 hp depending on which site you look at. The heads are 509`s 74cc with 208 160 valves . was wondering if 906 heads would be better on this engine as they are 174 exhaust valves. I know they would lower the compression bout half a point I have a set available to me. I want to put a larger cam like a 488 lift in the engine .... it has true flat top pistons no valve reliefs. I would like the engine to run as good as possible , it is a street car . Any input would be appreciated .

 

I would put the valves from the 906s. in the 509s, clean up the bowels under the valves and go from there.

The pistons you have are probably not 10-1.

 

The 906s are closer to 90 cc. So if your
Willing to shave them down to 80cc , or go with the 509s and bigger valves that is the question.

I would put.in. 2.14. 1.81 valves in the heads you have.
Open. Them up and go.......

 

Thanks Iowan, not sure on the compression but im pretty sure I read on one of the sites the 59 413 is 10-1 with 350 HP. Either way think I will just use the heads it has . Don't want to get into a bunch of machine work . Thanks again !