D-113
I used LT4 springs. seats and retainers, on my 113s with a similarly sized cam (0.503/0.510 lift with 1.5 rockers). They should be ok for 0.525 lift according to GM.
The only issue I had with these springs and retainers was insufficient retainer to seal clearance on the exhaust valves, when attempting to add seals to the exhaust valves.
The exhaust valve guides seemed to be about 1/8" taller than the intake guides. More surface needed for exhaust valve cooling I guess.
Note: No exhaust seals were originally present, but I had planned on adding them.
Therefore, I didn't use the intake syle seals on the exhaust valves like those used on both intake and exhaust on the ZZ4 style 113s.
For oil control on the exhaust valves I just used the normal o-rings and added 1.43" oil shields from comp under the retainers which are normally meant for larger springs, with the end result similar to the stock setup.
I didn't find any other oil shields that would be a better fit for the LT4 springs. If anybody has a source for these, please share.










