travperkins

question, im swapping out a small block chev for a 1999 4.8 and will be running a th350.. now from what I understand is that I need a flex plate spacer which I have found through summit......... does spacing the flexplate back affect the alignment of the starter on the flexplate as far as how well the teeth mesh up? maybe im missing something but seems like it would be an issue?


thanks much guys

Full-Force

iTrader: (11)

I dont think you will need anything if the engine came with the flexplate. I put a th350 behind my ls1 and had to go to junkyard to buy a flexplate off of a truck motor. The correct flexplate has the spacing in it. It will have an offset. Earlier style flexplates were flat. That wont work

Full-Force

iTrader: (11)

and the torque converter needs to be an ls1/th350 so it has the ls pilot/snout

travperkins

what year and size ls did you use?? I've gotten several different opinions from people.......

Full-Force

iTrader: (11)

it was the ls1 in my 99z28. I went with a ptc converter that was made for an ls1 and th350. I got the flexplate off of a 5.3 truck motor. An old sbc flexplate will bolt up but it will run against the starter housing. The ls flexplates are offset

Full-Force

iTrader: (11)

and when you bolt the tranny up you will not use the top bolt. Actually I think the top three bolts

travperkins

I'm doing an 99 4.8 out of a truck to a turbo 350...... I'm wondering if my LS is different. From what I can tell there calling the 4.8 is a gen III. Not sure if that's correct, I'm new to the LS scene.

Summit is selling a spacer for gen III LS to a th350/400 700r4.

Full-Force

iTrader: (11)

4.8, 5.3, 5.7, 6.0 they are all gen 3 ..

travperkins

Well that's even more info then I had before, and I thank you again...... Can you explain the ls1 ls2 ls3 etc.......

Full-Force

iTrader: (11)

ls1 is an all aluminum 5.7, ls2 all aluminum 6.0, ls3 all aluminum 6.2

the 4.8 and 5.3 are the hottest thing going right now in terms of conversions. They are cheap, make hella power, tons of aftermarket support, reliable, efficient, etc

most people just refer to all gm v8's from 97 and up as ls motors. Now you have lt1's which in my mind are still ls motors because the most previous lt1's from 92-97 were still based on the sbc

travperkins

Very interesting and thanks for the great info.....

Thanks for breaking down the engine info..... So my 1999 4.8L LS engine is cast iron with alum heads would be considered a gen lll LS?

travperkins

I'm sorry I keep bugging you about what is probably common sense but it's kind of confusing......

Full-Force

iTrader: (11)

yes ... no bother