$hawn

Whats the difference from the LT4 valve spring retainers than the Lt1's, the meterial? If so what are they both made out of? Also what about the keepers(locks) any different?

Mtrhds94Z

I know the LT4 retainers are lighter but not sure the material..

$hawn

Maybe there aluminum? Lt1's are steel? Cast iron?

Mtrhds94Z

I just stuck a magnet to one I got here, so it's steel..
Maybe they are thinner or machined more than the reg LT1 ones.. [I don't have an LT1 one to compare it to.]

NightTrain66

I honestly think they are the same.

Maybe Shoebox or a GM dealership employee knows of a difference but I have never noticed a difference.

NightTrain66

Compstall

I JUST finished this swap, and had that question myself. I don't have a scale that's delicate enough to weigh them, but honestly they both look the same, feel the same, etc. Retainers too.

Mtrhds94Z

IF they are the same, then all who buy them with LT4 springs are wasting their $$$...
Everywhere I read that they are 'lighter'?

Compstall

Like I said, if I had a digital scale I would have weighed them, but if there is a difference, I didn't notice it in my hands.

Mtrhds94Z

Not doubting you, [and Lloyd seems to agree...]
That is why my interest is piqued here..
Would be interesting to know if they ARE the same?
I find this info:

10212802 LT1 Cap, (Retainer) valve spring
10212808 Valve Spring Cap LT4 - ZZ4
These valve spring caps are used on 1996 LT4 Corvette ZZ4 engines as well as the special service only heads P/N 12556463. These are light weight caps.
Technical Note: Use with spring P/N 12551483.

Sure is interesting...
If they are in fact the same, I wasted the $$ on them when I swapped to LT4 springs...
Anyone got one of each, for measurements/weight comparisons?
Thanks!
Charlie

NightTrain66

they definitely "seem" to be the same. They are VERY close if they are not the same.

Even though they are possibly the same, the spring and retainer set up seems to be OK for a Hot Cam and 1.6 rockers. I do not know of anyone that has had problems with them but on paper, a better spring would be better. These only have about 100 lbs open and 280 open there is barely room before coil bind so you cant shim them for any more pressure. I guess it is the slower ramp of the Hot Cam that makes them suffice but you would normally like more seat pressure, more open pressure and more room before coil bind.

For anyone using the Hot Cam, Combination Motorsport has the 612 kit that fits with no machining and can handle up to .580 lift and is only like $80 for springs, retainers and locks.

After checking the specs and clearance of the hot cam springs, I am amazed that more people have not had problems but they seem to be OK. They just "should" have problems.

NightTrain66

95 Z/28 LT1

I believe the difference is that the LT4 caps are made of a cromoly steel.

$hawn

You wouldnt think gm would make them out of chromoly steel, considering there pretty cheap.

Compstall

Nighttrain66, we've been down the "these springs are better" road a billion times.

Anyway, it would be nice if someone had a scale to weigh the shims and see if there's a difference..