Auto tranny/tcase advice please

[bilfman]

Hi all,

I currently have a 79 crew dually 4x4, it is a454 w/ th400 with a np203. I am thinking of upgrading to a 4 speed auto and np 205. Any suggestions or suppliers for this swap. I have heard a 4l60e works well. But I am looking for a good smooth install. All advice appreciated.

Thanx in advance!

[andrewmp6]

A 454 would probably kill a 4l60 easy the 4l80 would be a better trans for a big block.If i remember right the 88-91 crew cab which was still the old body used the 4l80 and np205 or all else fail there is adapter kits to put a np205 on a 4l80.

[kwmech]

Originally Posted by andrewmp6

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If i remember right the 88-91 crew cab which was still the old body used the 4l80 and np205 or all else fail there is adapter kits to put a np205 on a 4l80.

1991 was the first year for the 4l80E. But your right a 4l60 won't last on a crew 4x.



As far as an overdrive to slow the gas guzzler down, you may want to look at maybe a Gear Vendor. Won't work in 4x though.

[andrewmp6]

I knew the 4l80 was offered in the later square body wasn't sure on the year tho,If your looking for the max mpg out of it a diesel swap will get it but isn't the cheapest either.

[Redcap]

The 4-speed/NP205 swap is easy. Did it to my K20.