got a friend who is in need of a tranny, got a burned car that has a tranny.
will the 700r4 work in the 79? if not, what will?
if it will work, will there be any mods that i need to do?
the 79 also is bolted to a 350 if it matters.
thanks

 

Yes it will work, but a few mods will need to be done.

The driveshaft will need to be cut down shorter, may need to move trans crossmember, will need a hoobs switch and some wiring or buy a kit to wire up the lockup...

Overall its a great swap and not that hard to do.. Try over at the trans. board on the message board at www.nastyz28.com

 

I've looked around, and talked to lots of people about this swap for a friend of mine. Here is what I've found out, you have to have the driveshaft cut, and the lock up kit which was posted above, and the cross member for the trans does need to be moved. My friend got a quote of $1700 to do thisswap at a shop(not including the lock up kit - an extra probably $150). As for if its worth it, most people say no, a th350 with a shift kit is a better performance trans, but the 700r4 has od which is better for the highway. I posted a thread for advantages and disadvantages if you want to see the replies, due to I am thinking about a th350 in my 88. Anyway to answer your question a 700r4 will fit, but for the cost you could almost be better off getting a new th350.

 

If you wanna do the swap the best and cheapest way is to do it your self,

$500 for the good used trans

$200 for a new stall converter or you find a good 10'' GM converter at a junkyard from one of the 4 cyl or 6 cyl cars that used the 700 r4. These will have a higher stall speed rating and smaller body. You can I.D the stall of GM 700 r4 converters by the decal or stamping on the flexplate side of the converter, then cross that number with your guide (find it online) to see stall

$20-40 bucks. useing a hoobs switch, and a brake pedel switch make the lock up. For info on how to make the lock up wiring and all lookin in some older chevy high performance mag. The went through it about 2 years ago, showin how to make it you self or look on the net, check out the turbo buick sites and the grand nat sites, them guys do it all the time.

$50-75 to have shaft cut and fixed

$0 to move cross member

This is a great swap and well worth the money for a daily driver, performance car or a car that has high rear gears like the 2.73's and all. The 1st gear ratio will make the final gear ratio for 1st lower, giving better start off power.
The OD will let you cruz at a much lower rpm, that saves on engine wear, gas, etc

If you want a performace over drive swap for higher hp engines and more racing check into the 200 4r transmissions. You might hear from alot of folks that the 200 4r is junk, but thats pure BS from folks that don't know what they are talking about. Overall they are much better than the 700, the 1st to 2en gear is better, the overdive is better, the trans is stronger, GM used them in the hi po cars of the 80's where the same car in norm HP/use had 700's, like the monte SS, the 89 turbo trans am, turbo regals, and the grand nat.

 

for what would be spent on a r4 he could prob get a built th350 or th400 fo the same amount