which trans to use?

my 88 square body ccd with 454-turbo 400 gets 6-7 mpg...any ideas on which trans to install hoping to get 10-12 mpg(wishful thinking)? I was told 700r4 could get you 10+ mpg...

700r4 is good it will have overdrive. you should get 10mpg

thanks...any special vehicle i should consider pulling one out of?

A few thoughts from someone who's looked into it before. Take it for what it's worth...

First, if you work your one ton like a one ton, a 700R will not last long. Second, if you're only getting 6-7 mpg in a TBI truck, something is wrong and that something needs to be addressed. Adding an od will not net you an additional 3-4 mpg. Third, od trannies on trucks of this size rarely end up netting enough of an mpg increase to justify the cost/hassle of installation.

See here:





Again, take it for what it's worth, but if it were me, I'd find out why I was only getting 6-7mpg. You ought to be knocking down *at least* 10mpg in that truck. I was getting 11mpg out of a Quadrajet-fed 454, TH400 and 4.11's.

"Man, swapping that 700R4 into my dually was a great idea" said no one ever. There's lots of guys who will tell you it'll hold, but not one of them will have to pay the repair bill when it lets go. Food for thought.

I could go with what JCampbell said on point 2, but not on point 1 and 3. thats just my .02

A properly built and maintian'd 700R4 will serve you fine as long as your not pull'n "very" heavy load's, I've pull'd my race car with a 700R4 for years with no problem.
the biggest thing is understand'n how to set up a 700R4, you cant just throw it in and take off.
it's just like the QuadraJet / Holley argument, the guy's that dont understand em dont like em.

P.S. - Campy is right, if your get'n 6 or 7 now you have other issue's as well.

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