volksmech1

iTrader: (9)

what are the pros and cons of using a 98 block as opposed to a later model block like an 02?

i am asking because i have heard they do not oil as well as the later model blocks. any info would be greatly appreciated

BIG_MIKE2005

iTrader: (116)

I'm also wondering. I might be able to get one for really cheap if not free, but if not a good block to work with I won't bother.

Ws6man2000

iTrader: (24)

i heard of 1 downside, the block can only be honed so much and just a bunch of a little different things

KCS

iTrader: (20)

If I remember correctly, older LS1 blocks had an oil crossover passage that wasn't as big as later blocks. In the back of the block you can look and see just two oil holes by the cam bore. Newer blocks had a passage that connected the two hole cut into the block and allowed for more oil the flow across.

As far as I know, thats the only major difference in the LS1 blocks. Compared to an LS6, they're supposed to be stronger because they don't have those windows below the bore for better bay-to-bay breathing.

BIG_MIKE2005

iTrader: (116)

So if you took the empty block to a machine shop to get cleaned & very slightly honed for some forged pistons basically the same saize as the stockers, could a machine shop enlarge the holes to allow more oil flow??

6techniques

iTrader: (7)

I dont see why you would have any problems running a 98 block...there had been plenty of them running in the 10's w/o a problem. So unless youre shooting for quadriple/high triple (750+)digit rwhp numbers, go with a 98 block.

BrianC98Z28

iTrader: (11)

570rwhp/540tq here on my stock 98 block. no problems. just changed the oil pump when i did the cam swap was all.

john563

iTrader: (17)

stock bottom,even the rod bolts? I have a98 as well H/C/I and Im thinking of adding a 75-100 shot to it and was concerned about the rod bolts

volksmech1

iTrader: (9)

thanks for all the replys guys. i ws just wondering how everyones expierence was with them

Taphee6

iTrader: (2)

The magizines say that the 98 has oil passages that make it weaker then the later years. Also, the honing is limited on the 98. That is what the perf mags state.

LS1-450

iTrader: (33)

It's not the hole size, but the passage way that connects them; & yes, a machine shop could enlarge the rear passage way between the holes. If we're discussing assembled block differences, the 02/later model blocks have stronger rod bolts & I recall something different about the pistons, but, am not sure on the piston. Am thinking it had something to do w/a coating.

Quick Carl

You can machine the oil crossover in the rear of the block to update to the newer design. I don't have a picture, but we have done it when re-sleeving the block. My biggest drawback to the pre-LS6 blocks is the un-equal length head bolts/studs vs. the equal length in later models for big power applications.

MCBRIZ28

iTrader: (2)

The weaker rod bolts in the 97 and 98 ls1 which is easily change if you need to reuse rods and only able to bore stock sleeves out .004 by gm specs also unequal length head bolts make them a little less desireable than other year models the oiling problem is easy to remedy like mentioned earlier . For a stock rebuild or mild set up I would still use it just change rod bolts or use aftermarket rods with a good set of pistons.

BlkHwk

iTrader: (8)

http://www.automotiverebuilder.com/ar/eb040538.htm

Steve - Race Eng

iTrader: (1)

I CNC machine the early blocks for the oil crossover when installing MID sleeves. I machine the iron truck blocks too because they lack the crossover as well.

I have photos of before and after so you can see what is involved.

Steve

KCS

iTrader: (20)

There ya have it.