700R4 in a 1970 K5? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*RED 1970* · 03-23-2010, 12:47 AM

Hey guys, I've been spending too much time on my other car and have neglected getting to the things that need fixing on my K5. Mainly, the transmission and transfer case leaks...

Turbo 350 feels weak, like it is about to give it up. I could fix it but I remember reading somewhere that a 700R4 has the same dimensions and would pretty much bolt right in between my 350 and NP205(?)

Any past threads you can point me to or new advice would be appreciated!

SeventyOne · 03-23-2010, 01:04 AM

unfortunately a 700r4 is longer than a Th350 and will require some mods to make it fit.

moving the engine and crossmember forward: preserves driveline angles and lengths. May not work with mechanical fan (not sure)...

moving the transfer case and crossmember back: may be less work overall considering your truck looks pretty nice in it's current state. Will need to modify driveshafts, 4x linkage, and crossmember location.

If that were my truck, I would rebuilt the th350 and go for a gear vendors overdrive unit - would only require a rear driveshaft mod, no crossmember work (that I am aware of) and it would save you a TON of work or tearing that truck apart just to fit a 700r4.

That's my 2 cents.

SeventyOne · 03-23-2010, 01:10 AM

here's a link to a recent 700r4 swap post (search is your friend

)

http://67-72chevytrucks.com/vboard/s...d.php?t=362803

Here's a cool link with the same arguement I just posted to you!

http://67-72chevytrucks.com/vboard/s...d.php?t=316798

By the way, how do you use the truck? Lots of highway miles screaming for an OD tranny? Would you be just as happy with a strong Th350? Some tough questions you need to ask about your truck and the way you use it.

Good luck with the decision.

03-23-2010, 12:47 AM	#1
RED 1970 Account Suspended Join Date: May 2009 Location: Portland, OR Posts: 89	700R4 in a 1970 K5? Hey guys, I've been spending too much time on my other car and have neglected getting to the things that need fixing on my K5. Mainly, the transmission and transfer case leaks... Turbo 350 feels weak, like it is about to give it up. I could fix it but I remember reading somewhere that a 700R4 has the same dimensions and would pretty much bolt right in between my 350 and NP205(?) Any past threads you can point me to or new advice would be appreciated!

03-23-2010, 01:04 AM	#2
SeventyOne Registered User Join Date: Mar 2007 Location: Oakland, Ca Posts: 1,381	Re: 700R4 in a 1970 K5? unfortunately a 700r4 is longer than a Th350 and will require some mods to make it fit. moving the engine and crossmember forward: preserves driveline angles and lengths. May not work with mechanical fan (not sure)... moving the transfer case and crossmember back: may be less work overall considering your truck looks pretty nice in it's current state. Will need to modify driveshafts, 4x linkage, and crossmember location. If that were my truck, I would rebuilt the th350 and go for a gear vendors overdrive unit - would only require a rear driveshaft mod, no crossmember work (that I am aware of) and it would save you a TON of work or tearing that truck apart just to fit a 700r4. That's my 2 cents.

03-23-2010, 01:10 AM	#3
SeventyOne Registered User Join Date: Mar 2007 Location: Oakland, Ca Posts: 1,381	Re: 700R4 in a 1970 K5? here's a link to a recent 700r4 swap post (search is your friend ) http://67-72chevytrucks.com/vboard/s...d.php?t=362803 Here's a cool link with the same arguement I just posted to you! http://67-72chevytrucks.com/vboard/s...d.php?t=316798 By the way, how do you use the truck? Lots of highway miles screaming for an OD tranny? Would you be just as happy with a strong Th350? Some tough questions you need to ask about your truck and the way you use it. Good luck with the decision.



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