Converter Q on 4.8LS swap keeping TH400

[Gene]

Doing a 4.8 LS swap in a 1987 4x4 which had a 305 w/TH400 stock truck. Keeping the TH400 but unsure about the torq converter. Should i get something more matched to the stock LS engine power or just keep the stock converter. I know its prob a little more HP but not much. I am ok with everything else just have no experience or knowledge About torq converters. Truck will not be used to tow anything but a utility trailer with a 4wheeler or lawnmower. Might put some 33” tires nothing bigger than that. If that Info is needed. thanks!

 

[Matt69olds]

Either get a converter made for the LS engine, or you need the adapter for the converter pilot. I’m not very well versed in the LS stuff, I think the distance from the converter pilot to crank is different, and a different diameter than the stock 400 converter.

I would think the stock converter would be fine behind a stock LS.

 

[Gene]

Thanks. I already have all the conversion parts. Just curious about the stall speed needs of the stock vs the LS engine. Thats what im curious about. Did some reading last night and see where some say diff things.

 

[RecklessWOT]

I feel like if the power is similar enough between the two engines (and I'm talking ballpark), you'll be fine. I've never heard of someone breaking a tranny over a 50hp difference (even a ****** transmission), especially not a turbo400, those are pretty stout transmissions.

Also, fwiw, it's spelled "torque". Nbd;Js

 

[Gene]

Yep on the spelling. thanks ok well im gonna just run what i have instead of buying new parts that i dont need.

 

[RecklessWOT]

Hah, I was just poking fun at the spelling thing. But yeah man I would honestly be very surprised if a 4.8 blew up a TH400, that's the transmission that was usually mated to big blocks