Well I removed a valve cover on the LT4 for the first time since I had a shop freshen it up when it was installed to find that there are 1.52 ratio rockers on it.

Is there any reason that they would have used 1.52 rockers instead of 1.6..which the LT4 should have had in the first place?? Maybe spring height was limiting the lift so that was the easy way out...I don't know.
The cam has .562 lift with 1.6 rrs. The springs look to be the same that were on my TA, Comp dual springs. Maybe the shop didn't know to use some +.050 locks or something to get more spring height.

Either way, I plan to trash the springs since they have way too much seat pressure and use the PAC1518s with 1.6s if there really no explanation for using the 1.52s..I know they are cheaper but that was not an issue when it was built. I'll check spring height with the current springs to see if it had something to do with height.

Just wondering

 

I have 1.52rr's on my car and the reasoning behind that was to make sure that I had enough piston to valve clearance... when everything was said and done I have plenty so maybe I'll throw in some 1.6's some time not too far down the road.


Besides that I couldn't tell you.

 

that is strange cause LPE seems to always suggest 1.6 RR on their cams,a true Lt4 comes with 1.6 RR from the factory.hmmm not cool.

 

1.6 MO LIFT.....not .02 more lift from upgrading from 1.5 to 1.52

 

Cool, just checking to make sure there wasn't some logical reason behind that I was simply missing, thx for the replies.
Piston to valve shouldn't be an issue as I know the cam was installed 0 degrees advanced, and its stock LT4 heads/valves and stock LT4 roatating assem.