I was curious to know if the 4t65eHD is the same bolt pattern needed for the LS series V8s? What tranny is it thats used in the FWD V8 Impalas? Lookin to do an LS2 swap... Just needed a lil info

Only the FWD 5.3L LS4 has the same bolt pattern as the 4T65HD.

Fastfieros is the only source for the adapter plate needed to connect a RWD LS engine to the 4T65HD.

Here is a thread you might find informative with a LS 427 connected to a 4T65HD:
https://www.fiero.nl/forum/Forum3/HTML/000083.html

Yes the LS4 has the FWD GM bell housing bolt pattern and no Lloyd is not the only one V8 Archie has a kit for mounting the RWD LSX engines to a FWD tranny just not sure if he has the electronics required to do the job.
The LS4 is an LS engine using a lot of LS6 parts and can be modified with other LSX parts to make a lot more power if that is what you are after with out the need for adapter plates and the LS4 is shorter then the other LSX engines making for an easier fit in the Fiero. Dan

quote Originally posted by FIEROFLYER: Yes the LS4 has the FWD GM bell housing bolt pattern and no Lloyd is not the only one V8 Archie has a kit for mounting the RWD LSX engines to a FWD tranny just not sure if he has the electronics required to do the job. The LS4 is an LS engine using a lot of LS6 parts and can be modified with other LSX parts to make a lot more power if that is what you are after with out the need for adapter plates and the LS4 is shorter then the other LSX engines making for an easier fit in the Fiero. Dan

Archies kit is based on the 168 tooth flywheel and that flywheel will not clear the side of the automatic transmissions... as such his LS kits are manual only. Fastfieros adapters are auto only...

Actually I believe I may just go with teh LS4 anyway, after doing research on it, much of the engine can be swapped with parts from the LS2 and made to have quite a bit more power. Thanks for the info.

Use the transmission equipped with the ls4...

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1986GT 4-speed DOHC and 1987GT Auto

quote Originally posted by Flyboy81: Would the 4T80E be a tranny that I might wanna look into?

I am the only one that made adapter plates with all necessary hardware for the 4T65eHD application to bolt to the GEN 3&4 applications that I know of. Archies is based on larger flexplates, and using the TH125c.

The 4T80e has a huge tailshaft housing and will not fit down the side of the engine block on SBC / GEN3&4 applications. The N* is narrow at the bottom area to have clearance on the 4T80.

The 6T70 will bolt to a LS4, but no electronics to run it. I made an adapter plate for the 6T75, but again no electronics to run it 3rd party, but I have a way with using the L76, its just expensive.

http://www.fastfieros.com

[This message has been edited by FastFieros (edited 11-25-2009).]