quick question im installing a set of 243s on my 370 current pr height is 7.400 i need to get the heads cleaned before i install them. Not sure how much they take off if any to get them good and clean. But do they take off enough to change my pr height? and will switching from 918s to patriot golds change anything with pr also thanks guys.

 

As long as You're heads are'nt warped at all usually all that is milled off is .001" - .002" to clean up the mating surface so no it won't affect You're pr length needs any . As far as the springs go , the valve rocker geometry will be the same because the rocker rides on the valve stem which will be the same as it was . The things that affect pr length are cam base circle changes , lifter wear or changes , cylinder head milling (more than .002") , rocker arm changes and or wear , valve changes and/or wear and valve seat wear . By changes I mean installing different brand parts and by wear I'm talking about wear over time and miles .

 

well I installed the comp trunion upgrade on my stock rockers if that makes a diff but I don't think that would effect the ratio.