TH400 to 700r4 HELP!!! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

muscletruck · 04-12-2004, 09:51 PM

hey guys and gals.... i want to swap out my th400 ou for a 700r4 i need some help in the gas mileage department... i wanted to knwo if anyone on here has done that.... what do i need to do?? and hwo much did it cost all you? new driveshaft? new yoke? cross member? anyehlp would be awesome....thanks everybody...oh 78 crew cab dually....thats what its goin in....thanks again

Russell · 04-12-2004, 11:56 PM

Make sure you get that 700r4 built up a bit if you are putting it behind that 454...

That engine will eat a stock 700r4 for dinner if you don't do any mods to the tranny. The 700r4 has a bad rep for being quite weak, and even a 350 has the capability to toast it.

toytruck · 04-13-2004, 12:14 AM

Everybody tells me the same thing. How about some 3.73 gears? That would help some. I'm in the same boat as you.

muscletruck · 04-13-2004, 01:08 AM

oh ok thanks... ya the previous owner built the motor up a little aswell its pumpin about 300-350 ponies at the fly... so build it... thats not so much the problem though... i knwo alot of tranny guys... i just need to figure out hwo to get this tranny to work with my truck.... oh man... maybe i shoudl slap a 4 cylinder in it... haha that would great!!!

04-12-2004, 09:51 PM	#1
muscletruck Registered User Join Date: Jan 2002 Location: anahiem,ca,usa Posts: 201	TH400 to 700r4 HELP!!! hey guys and gals.... i want to swap out my th400 ou for a 700r4 i need some help in the gas mileage department... i wanted to knwo if anyone on here has done that.... what do i need to do?? and hwo much did it cost all you? new driveshaft? new yoke? cross member? anyehlp would be awesome....thanks everybody...oh 78 crew cab dually....thats what its goin in....thanks again __________________ i think i found me truck! 78 Crew Cab Dually 454/TH400, Dual Flows, Edelbrock Intake, Cam, Lifters, Billet Grill, K&N Airfilter, Grant Steering Wheel, A/C, soon to be power windows and locks, lots of plans for this... ....gas prices go down please

04-12-2004, 11:56 PM	#2
Russell Professional Grade Join Date: May 2003 Location: Fort McMurray, Alberta Posts: 7,915	Make sure you get that 700r4 built up a bit if you are putting it behind that 454... That engine will eat a stock 700r4 for dinner if you don't do any mods to the tranny. The 700r4 has a bad rep for being quite weak, and even a 350 has the capability to toast it. __________________ 1995 Chevrolet 2 Door Tahoe (6.6L LBZ Duramax / ZF6 / NP241 with 1 ton solid axle swap)

04-13-2004, 12:14 AM	#3
toytruck 5-7 dropped 87 CC Dually Join Date: Sep 2003 Location: bay city mi Posts: 326	Everybody tells me the same thing. How about some 3.73 gears? That would help some. I'm in the same boat as you. __________________ I rather be in my 77 Sanger Picklefork Jet Hydro!

04-13-2004, 01:08 AM	#4
muscletruck Registered User Join Date: Jan 2002 Location: anahiem,ca,usa Posts: 201	hmmm oh ok thanks... ya the previous owner built the motor up a little aswell its pumpin about 300-350 ponies at the fly... so build it... thats not so much the problem though... i knwo alot of tranny guys... i just need to figure out hwo to get this tranny to work with my truck.... oh man... maybe i shoudl slap a 4 cylinder in it... haha that would great!!! __________________ i think i found me truck! 78 Crew Cab Dually 454/TH400, Dual Flows, Edelbrock Intake, Cam, Lifters, Billet Grill, K&N Airfilter, Grant Steering Wheel, A/C, soon to be power windows and locks, lots of plans for this... ....gas prices go down please



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