Bought my first 88-98 today

Brett Anderson · Jan 23, 2021

Bought a 98 gmc rcsb today. Super nice truck but is a 4.3/auto. Bought to to do a hot rod shop truck and I’m gonna put one of my ls in it. From what I’m reading I hear different things. Will the 4l60 in it work behind a ls, I’ve been told the v6 trans have some different stuff and I’m also not sure if the transmission is different in 98 vs 99-up. Don’t wanna waste any money if it’s not gonna work

1997 · Jan 23, 2021

Pics?
Welcome aboard.
2 wheel drive?

Frank Enstein · Jan 23, 2021

To hook your trans/torque converter to the LS engine you need HUP-HP4004X and HUP-HP 3795.
Both of the numbers are Summit Racing numbers.
If you have the trans gone through and put a TCI Pro Super Kit in it the V6 trans will be fine.

letitsnow · Jan 24, 2021

Most of us will recommend that you put a 4l80e in at the same time as the LS.

Remodelmaster · Jan 24, 2021

Welcome to the addiction!

frito-bandito · Jan 24, 2021

Welcome to the forum! @Dropped88 might know this answer

Dropped88 · Jan 24, 2021

Yes that trans will work along with adapters mentioned above but I THINK there is a stock flexplate you can get by with. Because I remember seeing that at one time but let me research that part

stutaeng · Jan 24, 2021

Here you go: https://redirect.viglink.com/?forma...809959-will-4l60e-out-v6-truck-fit-5-3-a.html

According to this source, the V6 trucks up to 98 got the smaller 298 mm input shaft design.

My 99 NBS Silverado 4.3 came with the 300 mm shaft (also had a top bell housing bolt hole that had no bolt because the SBC based engines don't us that one.).

I would think they switched to the 300 mm design for all 4L60 to make them compatible with any engines during the transition period.

Seems like the adapter was addressed, so maybe this information is not relevant.

Brett Anderson · Jan 24, 2021

Thanks. I’ve been running ls with non ls trans for a long time. Usually powerglides/th400 in racing apps. I’d have a converter made with ls snout and all. I guess I need to find out about I put shaft. If it’s small then I’d probably either change it to a diff overdrive or run a th400

1ton-o-fun · Jan 24, 2021

If it's no big deal either way for a beginning of the project, I would say 4l80 is a no-brainer. It's basically a th400 with overdrive. If you're already racing ls's, you're most likely not planning to drive this truck like grandma going to church.
Just my 2 cents...

Bought my first 88-98 today

Brett Anderson

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1997

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Frank Enstein

Best. Day. EVER!

letitsnow

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Remodelmaster

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frito-bandito

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Dropped88

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stutaeng

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Brett Anderson

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1ton-o-fun

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