I dont want to try this and kiss my motor good bye, But i was thinking about getting 1.6 roller rockers on my 388 stroker.. here is the problem i herd that vaulve piston clearance might be a problem... i have 9:1 flat tops in it with 5.7 rods 74CC heads with a comp high energy camp .485 lift ???? it has the 400 stroker crank in it by eagle racing and is bored 4.060... if this evon will work how much inprovment will this make over my stock tap rockers what could it shave off track time..????

any help is good help!

 

valve clearance might be a problem, but you already know what it is with the 1.5 rockers right? most likely since you never checked it when you put it together you can remove a pair of valve springs and install a set of soft springs and check it with a indicator. there isn't much chance of having any clearance issues untill you get around .65 lift with flat pistons.

 

be careful as changing something like this can make or break you. i thought i needed 1.6 and in all seriousness the 1.5's are much better.

good luck.

 

Make or break you huh..? well i thought (proporly ajusted) they could onley do good flowing more air in and back out of the heads... your car might still be computer controle so it never made any "real" change because you didnt change the amout of fuel you gave it to make a engin run optimal you need 14.8 parts of air for every one part fuel this is true with race engins and stock engins so increasing Just AIR flow will probley hurt you... this is just my inside. if you know somethine i dont know LET ME KNOW... every bit of info helpss

 

Increasing your rocker ratio should give a nice power gain with a cam in the .485 lift range.
With stock components ---> The piston to valve clearence should be ok, the 383 and 388 have a normal piston height as compared to a normal height of the 350 and 355. Deck clearence...
Now for the BUT... If you are to change the rocker ratio on a pre-assembled high performance engine than you should verify the valve to piston clearance before you run it. If you don't, a whole lota good money could be lost.