Piston to valve clearance.

[Slidenotch]

So first off I have a stock 302 short block, a tfs stage 1 cam, tfs 170 heads, and 1.7 roller rockers.

I've heard many things about piston to valve clearance. I do plan on checking them but i just want to get some opinion on them before i have to take it back apart because of it. I've heard you can run up to 550 with the tfs heads and stock piston but i've also heard you can only run up to 520. From my math my lift should be around 542 and 520? Correct me if im wrong. The lift with 1.6 rrs is 510 and 490.

Just looking for some advice if i should go ahead and fly cut the pistons or just go with it and see where it leads.

Thanks.

[psychotexan]

check it but i know of multiple people runnin tfs stage 2 cams on the stock bottom end with tfs tw heads!!!

[thatdavidkid]

I always suggest checking, one "stock" shortblock may be fine where another may have been rebuilt and may have issues due to differences in piston manufacturing. I have "stock" replacement pistons in my car with a crane 2030 cam (533/544, 220/222) with 2.02/1.60 valves and it's fine but my buddy had similar pistons but specifically cut for tw heads with a tfs2 cam and tw heads and had contact issues until he retarded the cam.

[Slidenotch]

So far I think it will be good until .550 lift. I have also saw stock short blocks running a stage 2 cam and the stage 1 with 1.7s is basically the stage 2 without the duration. I think it shouldn't be an issue but im still going to do the clay trick and know officially. And if there is any problem, i'll just fly cut the piston and go get a stage 2 with 1.7s. If im cutting them, I'm going to make it worth it.

[WarHorse]

check it but i know of multiple people runnin tfs stage 2 cams on the stock bottom end with tfs tw heads!!!

Other considerations are whether the heads have been shaved in the past and what gauge/thickness your new gaskets will be. I would seriously consider having a shop check the clearance. What type of pistons are you running?

[Slidenotch]

Other considerations are whether the heads have been shaved in the past and what gauge/thickness your new gaskets will be. I would seriously consider having a shop check the clearance. What type of pistons are you running?

I know the heads haven't been shaved. the guy the was running them had .30 over dome pistons and only have 11 to 1 i think. But they are just the stock pistons. I'm gonna be doing the clay check before final assembly. I just wanted some other peoples advice. If a bunch of people are saying its gonna hit, then i was just going to have the pistons cut.