95 lt1 block?
 

Is it legal to run a regular old style Chevy block rather than a LT1 block in a 98 Camaro in stock eliminator ?

Re: 95 lt1 block?
 

Yes, as long as the main bearing size is the same. In other words, you can't run the small main journal Chevy pre-1968 block.

The blocks are NOT a direct replacement. The LT block has a completely different cooling routing system, unique front drive distributor, different timing cover, etc.

Others have converted an LT engine to a earlier generation block, but it's not that easy.

Re: 95 lt1 block?
 

Maybe in Superstock, but in stock you must use the Opti-spark, which requires the LT1 block.

Re: 95 lt1 block?
 

MSD and stock GM Opti-spark's will work the traditional style sbc blocks.

Re: 95 lt1 block?
 

Inquiring minds want to know how to do this ? What would you use as a waterpump ?

Re: 95 lt1 block?
 

Standard sbc water pump with spacers to clear distributor. Water flow can be either direction, these motors don't see enough temperature to need the reverse cooling.

Re: 95 lt1 block?
 

Seems to me the issue is how to adapt the front cover to the old style block . Isn't the shape and bolt pattern very different . Also wouldn't the water in the heads be deadheaded .

Re: 95 lt1 block?
 

Rare they are but they did make Bowtie LT-1 blocks....

They were made in a std 4" bore size and a larger bore....4.125"

I took delivery of 1 for someone who found 2 or 3 available somewhere.

I was aware that Bowtie blocks could be adapted for use in SS with a belt drive distributer but never knew of or saw one in Stock adapted somehow to drive an Optispark distributer with the LT-1 timing cover....on a std type block....

An Interesting topic....

Re: 95 lt1 block?
 

Drew is right and it isn't all that complicated. You do have to weld up the water passages on the LT1 heads (legal by tech) and fill in the top of the timing chain cover with epoxy for the LT1 to adapt to a SBC block. The LT1 timing cover has somewhat of an overbite is the best I can describe it when placed on a SBC block.

There are two water passage plugs on the heads that you remove with an adapter that bolts on to adapt to an -AN fitting. A standard SBC water pump with enough spacers to make a good border wall will be necessary to clear the Optispark or MSD. I suggest that you use the largest water return lines and -AN Y fitting coming from the heads that will fit.

Hope this helps.

Re: 95 lt1 block?
 

I forgot to mention that the reverse cooling for these engines was a way to somewhat battle detonation on pump gas and utilizing higher compression for a street car. We can and do run much higher octane with our racing fuel so it is a moot point on how it cools from the top down or bottom up.

Just make sure it cools.

Re: 95 lt1 block?
 

Why not just use a LT1 block and not have to do all the modifications.

Re: 95 lt1 block?
 

Because a Dart or a Bowtie block is better.

Re: 95 lt1 block?
 

LT-1 blocks have a rep for being poor on ring seal on the center 4
cylinders even after filling the water jackets.

I was told that by Woodro Josey when I built one and after racing it some and leakdown testing it, that is exactly what I found...

That block was filled and at .040" over...a 2 bolt main block...

Re: 95 lt1 block?
 

Would you have to weld in some sort of boss to hold in the oil pump drive ?

Re: 95 lt1 block?
 

I was trying to figure the same thing. Would like to know before starting a new build.

Re: 95 lt1 block?
 

I ran the LT1 block for 12 years with no issue