Trans swap?

5

Asked by Apr 08, 2009 at 09:52 PM about the 1990 GMC Sierra 1500

Question type: Car Customization

My truck has the 700r4 trans and I cant get one but I did find both the 350 and 400 at my local juckyard at a price that I can afford. Now will either of these work in my truck? I know after searching online that with the 400 I would have to get either the 9" tail piece or a longer driveshaft but what about the electrical connections? Will the truck still run right with these other trans in it?

3 Answers

155

The 700r4 is a fully hydraulic transmission, no wires or transmission control modules to worry about. Depending on the engine you have, a turbo 350 should run in your truck no problem. The 400 isn't as much of a bolt in as the 350 though. Also, keep in mind the 700r4 is a 4 speed transmission, and the 350 is a 3 speed, so your fuel mileage will suffer. But, the 350 is a lot more bulletproof than the 700r4. It all depends on what your willing to sacrifice.

45

i would try my best to get a 700r4 because you will of course get better mpg but you top end will be great now if your pulling something the 700r4 is still good but the th400 if u get an older one will near about be indestructable its greatest power is in the low ranges though but i personally like 700r4 i have a shift kit put into mine and it is an automatic and a stall converter it have never given me any problem and i have a greater top speed compared to a th400 or th350

I need a good tranny for a 94 gmc with a 6cyl ....and one for a 88 chevy with a 350

Your Answer

Add photo

Related Questions

  • transmission swap ? 4 answers

    i have a 2000 gmc z71 sierra 1500 with 236000 miles and a 4L60E trans the truck shifts trough 1st 2nd and 3rd just fine but wont go any higher. is this a big expensive fix or something simple ,and i h...

    2000 GMC Sierra 1500 SLT Extended Cab Stepside SB

    -

    Car Customization

  • how involved is a 4.3l to a 5.7 in a 1998 gmc 1500 1 answer

    i have a 1998 GMC ext cab 2wd, 100k with a 4.3 in pieces,, (aren't kids great). It has a v.nice body, Haven't been able to find a decent used 4.3. ( But I'm also Not sure what years are compatible,...

    1998 GMC Sierra 1500 C1500 SLT Extended Cab SB

    -

    Car Customization

  • motor swap 7 answers

    I'm looking at replacing the vortec 350 in my truck with a 6.5 turbo diesel. I don't need hate on my motor of choice, It's perfect for what I'm doing. My question is do I need my computer replaced (or...

    1998 GMC Sierra 1500 K1500 SLE 4WD Extended Cab SB

    -

    Car Customization

  • Can I upgrade my 305 V8 in my 1993 GMC K1500 with a 454 V8? 1 answer

    I'm wishing to upgrade my engine for towing and hauling capabilities and wondering if a 454 will fit my 1993 K1500? I know I will have to replace and match the trans, electrical, and computer junk but...

    1993 GMC Sierra 1500 K1500 SLE 4WD Standard Cab SB

    -

    Car Customization

  • 1993 gmc Sierra motor swap 2 answers

    I got a 1993 gmc Sierra with a 4.3 tbi v6 with a nv3500 5speed trans motor blew I'm trying to stick a carbureted 305 in it anyone no what I need to make this go smooth

    1993 GMC Sierra 1500

    -

    Maintenance & Repair

Sierra 1500

Looking for a Used Sierra 1500 in your area?

CarGurus has 67,884 nationwide Sierra 1500 listings starting at $2,484.

ZIP:

Search GMC Sierra 1500 Questions

GMC Sierra 1500 Experts

#1 dragonflyoffshore
dragonflyoffshore
Reputation 5,010
#2 John Saffrahn
John Saffrahn
Reputation 3,540
#3 Glenn Clingenpeel
Glenn Clingenpeel
Reputation 3,150
View All

Related Models For Sale

Used Ford F-150
2,179 Great Deals out of 206,277 listings starting at $1,499
Used Chevrolet Camaro
218 Great Deals out of 30,799 listings starting at $1,217

Used Cars For Sale

2017 GMC Sierra 1500 For Sale
35 Great Deals out of 43,802 listings starting at $20,121
2016 GMC Sierra 1500 For Sale
82 Great Deals out of 3,661 listings starting at $17,888
2015 GMC Sierra 1500 For Sale
101 Great Deals out of 3,925 listings starting at $15,400
2014 GMC Sierra 1500 For Sale
108 Great Deals out of 4,142 listings starting at $14,495
2013 GMC Sierra 1500 For Sale
67 Great Deals out of 2,002 listings starting at $9,999

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.