Anyone forsee problems using the LT4 springs, retainers, keepers w/ the Stock L98 cam w/ 1.6 rr (lifts to .443/.459)?
Will the spring seats need to be cut for these springs?
1.32" OD
105lbs @1.77"
275lbs @1.25"

I see it can handle the lift. But is it overkill?

 

you'll need to machine the seats larger, stock spring diameter is 1.25

 

IMHO if you're going to go to all the trouble of putting new valve springs in there, you should use something decent instead of GM's POSs.

But to answer the question that was asked, no, a 1.32" diameter object will not fit into a 1.25" diameter hole. Usually. However, tolerances on that particular part of the head machining aren't very tight; it may jam down in there far enough, especially if you shim yhem a few extra thousandths to make its pressure approximate something useful, because they're made out of such huge wire (being typical stockish springs, unlike performance ones) that the part that would actually have to go down into the pocket may squeeze in there.

Ask me sometime how I really feel about GM valve springs.

 

Well,

I have these already not being used, and just need something that will work. I figure if the seats need cutting, then they will already be done for down the line when I upgrade the cam and need better springs. Didn't really want to buy springs twice, especially since I've got these retainers, keepers too...But, if the GM springs are that bad...

The ones that came with the car are still on there...192000+ miles. How bad can they be?

 

Well, new stock springs are better than 192k mile stock springs, for what it's worth. But they're still just GM springs; lots of people have posted all manner of horror stories about the HOT cam kit and spring-related malfunctions, usually wiped cam lobes or broken springs, and that kit has seemingly better springs than the regular LT4 ones. Still pretty crappy though obviously.

But, your lift is only just barely into the range of the mildest of aftermarket cams, and you'll still have the gentle, lazy stock ramps that give sluggish valve action; so the spriings will only see a minimal stress increase over the original.

Good luck.