MatI probably wouldn't run thinner head gaskets, a certain thickness is needed to allow good sealing. The base gaskets can be done without to bump the compression up. The easy way to check head and valve to piston clearance is with a dry build and some plastacene. Clean the piston and very lightly oil the valves so they don't stick. You should have a minimum clearances of about 2mm valve to piston and about 0.7mm piston to head.Assuming I could have Head and base gaskets made to order (which I can) How thin could they be? I've been told by some that they run no base gasket on Sports with no problems.
How much clearance is there to work with?
I've got Strada pistons and will be running a Sport cam (just installed)
but need to raise compression.
The aluminum gaskets from the kit measure 1mm each.
No, all the rockers were the same from 119 to 507cc. The ratio doesn't change, you might just get towards the end of the adjuster range and/or into poor geometry. The difference is just 1.25mm (half the base circle difference) and if you leave out the base gasket you'll get some of that back. You could always make up a set of longer pushrods. The ends can be removed and re-used (as is or lightened). Some people use arrow shafting as a lightweight alternative.Also the Strada cam I took out and the SPORT Cam I put in are ground on 20mm base circles, If the later L5 and 2+2 cams are on a 17.5mm base circle would that not throw the rocker arm ratio out? Are there early and later rocker arms?