ownor

iTrader: (5)

Hey folks,

is there any chance one of you guys have a set of connecting rods and flat-top pistons out of the 90 / 91 / 92 L98 kicking around that you would like to transform into cash?

please let me know!
thanks

3rd gen Will

iTrader: (8)

I have 6, possibly 7! Not a complete set though.

it is my understanding that the LT1 stuff is the same piston, but with better rods. That might be an option for you as well.

Johnny Blaze

iTrader: (15)

Are 90-92 pistons and rods different then 87-89?


And yeah, the LT1 powdered metal rods are supposed to be better, and pretty cheap.

3rd gen Will

iTrader: (8)

The (90?) 91-92 pistons are flat top 4 valve relief.

IIRC the older ones have a slight dish to them.

3rd gen Will

iTrader: (8)

Yea I know the PM rods are better, had them in a crate motor I beat the living hell out of with nitrous to boot. I am just not sure if all year LTx's got them or just the later years, I know my buddy's 97 LT1 Z had them.

Twin_Turbo

iTrader: (25)

90-92 pistons

Johnny Blaze

iTrader: (15)

I'm curious why the op wants these, as apposed to a replacement hypreutectic.

I have had a hard time finding a 350 block that can stay standard bore letely anyway.

3rd gen Will

iTrader: (8)

My block was the original 91 block, never had any work done to it, they had to go .030 over to line up the center of the bore with the crank (according to my machine shop.)

ownor

iTrader: (5)

Will sounds like you had what they call a bore shift, where the bores are not (well not perfectly FWIW) aligned with the crank centerline.
for the other comments, as TT already indicated these are the 90-92 pistons with a smaller dish (imho results in 9.5 vs. 9.3:1 with the 64cc heads)

anyways, i'm now actually looking for a whole 94-up LT1 rotating assembly since from what i gather these are lighter, stronger and boost CR, which is exactly what i'm looking for. i don't intend to get the block bored, and stock stuff should suffice my power goals and fits the bill, literally.
i'm looking at buying a local one but will come back if i dont find one
thanks!

3rd gen Will

iTrader: (8)

Bore shift, that is pretty interesting.

IIRC the LT1 rotating assembly is same exact piston as 90-92. Better PM rod and a Nodular Steel crank VS the nodular Iron in the 3rd gen Steel being lighter and stronger. if you still run a stock L98 head (64CC Chamber) you will not go up in CR. The LT1 heads have 58cc chamber that is why they have the 10.4:1 cr

ownor

iTrader: (5)

Not sure if it was referred to as core shift or bore shift, but it's about little alignment flaws in the casting process which are no problem for a standard road mill, but might be worth straighting out for HiPo builds.

for the LT1 rotating assy, from what i've read the early LT1 pistons are the same as the late L98, same for the 'pink' rods. The PM rod was introduced in early 94 and was standard from 95 onwards, the pistons were changed to an updated hypereutectic piston with thinner rings imho. Piston tops are about the same cc-wise. Imho just the LT4 used the nodular iron crank, but the standard LT1 crank should be lighter than the L98 crank still. Plus it's (supposedly quite nicely) balanced for the lighter rods and pistons.
The LT1 heads have 54cc btw
Thanks

Johnny Blaze

iTrader: (15)

Have you measured your bore, to see if it can stay standard?

ownor

iTrader: (5)

Frankly i need to admit i haven't, but would have expected it to be okay since i can still see a nice crosshatch and the top ridges are not bad either.. Oh well what do i know

3rd gen Will

iTrader: (8)

I thought LT4 heads were 54cc LT1's were 58cc...Oh well My LTx knowledge is minimal cause I don't care for the engine.