Just been reading about 50 old posts on TH350/400 swaps with LS1's.
Most say to order the 6.0L Flexplate and spacer (01+ model)

Besides the 6.0L flexplate having old SBC Converter bolt pattern is it the same size/dimension/dish as a normal LS1 flexplate?
Eg. with my 01 LS1 flexplate can I just drill holes for converter to bolt to and use the 6.0L spacer? Will this space the converter in the same spot as the 6.0L flexplate and spacer?

 

Well if you use a converter that is built for a LS1 you wont need the spacer then al you have to look in to is if the bolt holes are going to line up. If you get a 98 flexplate or a one of the TCI ones you wont have a problem.

 

I had a custom TC built for my set up. They asked me what flexplate I was running and built the TC so it would bolt right to the flex plate. If you call and tell 'em what you need they, (whoever you buy the TC from) might custom build it for you!

Ken

 

I just checked, my flexplate is off a 99 model engine but has dual bolt pattern, I bolted an old TH350 converter up to test it. Bolts up perfect without elongating the holes.

Do I need a spacer with the 98-9 flexplate or is the spacer only needed for a 6.0L flexplate?

 

the spacer really has nothing to do with the flexplate. it's needed because the crank is too short to support the front of the converter. i'm using a regular 5.7 flexplate and the spacer. i redrilled a second set of holes. it's way , way cheaper. now if you need another converter anyway then it's another story.

 

5.3 racer, are you using the GM 6.0L spacer with a stock 5.7L flexplate?
No spacers needed for converter bolts?

 

no, in my case i don't need any spacers to run the converter into the pump.

 

So what does you setup consist of?
Regular TH350 converter
98 flexplate
Anything else?

 

Speaking of TH350/400 swaps:What are you guys doing about your VSS?

I have looked at old posts but wanted to get a consensus.

 

not sure the year of the flexplate but yep, that's what i'm using. actually i'm using a BOP turbo 350 so i have an adapter plate(1/8") between the engine and trans. so i'm using a 1/8" washer between the flexplate and the converter.

 

Can I ask what brand or where to get the adaptor plate from?

 

do you mean the adapter plate i'm using to bolt a Buick Olds Pontiac th-350 to a chevy engine or the crank spacer? the adapter is a TCI-60172. about $50 from any speed shop. the crank spacer came from gm part #12563532, $25. it also requires 6 bolts part#12563533 $22.