allblowdup

I know that the ls7 liners are longer and the extra head bolt but other than that I don't about any differences in the block itself. could I use ls3 parts inside a ls7 block if was so inclined?

Sales4@Texas-Speed

iTrader: (4)

LS7 blocks are a 4.125" bore and LS3 blocks are 4.065". There is no way to put LS3 internals inside of an LS7 aluminum block.

allblowdup

I should have clarified myself better. I am looking at doing an 4.185 bore x 4.25 stroke in an alum block. I can get an ls3 sleeved or sleeve a ls7 if the rest will work fit.

Stang's Bane

iTrader: (22)

Start with the ls3

Steve - Race Eng

iTrader: (1)

The LS3 or LS2 block for that matter are better and less expensive choices for sleeving unless you already own an LS7 block. I actually prefer the LS2 because the old sleeves clean out better during machining.

The center main bearing bulkhead is stronger on these two than on the LS7 block. You are giving up the steel main caps but the stock powdered metal caps are more than adequate for most builds.

I have sleeved many blocks, both dry and MID for 454" and larger builds including the 468" block in the Hot Rod Magazine cylinder head test article.

Steve

Sales4@Texas-Speed

iTrader: (4)

Ok, sorry I didn't read the first post right. In this case I would start with an LS3 or LS2 as Steve has said. Those LS7 blocks are pretty expensive to start with.

BlueFish

iTrader: (1)

Steve has done just that with my blown LS3 block (MID Sleeves) and I now have a 434ci (4.155 bore and 4.00" stroke) with LS7 top end and works great. Make sure to complete the block with Ported heads and as Steve would recommend Evans water pump and NPGr coolant.

Karn

KCFormula

iTrader: (4)

Can you run a 4.25" stroke in a short deck block?