Can i go from 1.6 to 1.7 roller rockers with out a problem with piston to valve clearance.I'm running a stock bottom end with Edelbrock RPM heads and intake. Will this work , has anyone tried this with this combo ??
Not sure what an "re/re swap means". Anytime heads with bigger valves, and cams with more duration are swapped in p to v should be checked unless the owner's willing to take the risk that clearance is insufficient.
The ratio change reduces clearance very little. During overlap when clearance is tight, the valves are usually open in the range of .050" while the piston is the closest to them. If you multiply (1.7/1.6)X .050" = .005" -- you only lose about 5 thousandths of an inch clearance. Your problem is you don't know how close you are to start with. So unless you're willing to measure, you'll have to be content with a 'guess' that 5 thousandths less than you have now is gonna be ok.
It means that Edelbrock says that you can take the stock heads off and replace then with there alum heads, in other words there a direct bolt on. Hope this helps .
myroc - As I mentioned before, even with supposed "bolt on" replacement parts, p to v clearance can be a problem. Almost every aluminum head or aftermarket cam out there is designed to simply "bolt on" the 5.0L - but that doesn't mean that all of them will go on without potential piston to valve interference issues. As you move forward, as mentioned before, anytime you add bigger valves than the reliefs were designed for or a cam that opens the intake valves sooner/closes the exhaust valves later, piston to valve clearance should be checked. Good luck with your changes.