Post by Pontiac1976 on Jun 14, 2007 16:18:32 GMT -5
73-87 swaps for drive shift
Well on the 8' bed the with the TH400 the drive shift need to be longer if your switching to a TH350 or 700R4.
With the 350 or 305 &TH350 step side switching to a big block and TH400 the drive shift should be ok just have to swich the trans yoke to the 400 style.
For the TH350 to a 700R4 the drive shaft is ok.
You will need to put a lock up switch in the trans if you want to make good use of the 700R4 & now the time to do it be for it in the truck now I think this link covers most what you should do if not it is covered in the Trans list under one of the titles 700R4 link: bowtieguy.proboards33.com/index.cgi?board=700r4&action=display&thread=1086900893 82 was the first yr for car to get the 700R4. Late83 Early 84 was the first yr trucks got the 700R4
If your lucky you can get the wireing from the 84-87 none fuelie Truck that had the 700R4 all ready and it plug & play all the way if the Case is a 82-87 that yr's in clude cars 82 was the first yr for the 700R4 , 87 was the last yr that style tail shaft.( as said by bowtie guy )89 after went cpu full shifting. But most all the gut up to 94 will fit the 82-87. But after 89 they need the cpu full wiring to work the best. You can buy a pretty nice second hand 90-94 700R4 and get most of the up graded parts in it swap all the good and better parts out, then buy any better one, or one you need to up grade if you get a decent one this will cut down on the rebuild & up grade. there is in the very bottom best links there some for the 700R4 you can see parts they say should be up graded what yr's that GM started to up grade there newer 700R4's for the parts. I do not have time right now check all the topicfor the one I tlking abut I will add some when i get a chance.& other might help you to .
I was lucky because the 1984 I got the wireing from had duel set up from GM it was set up for 350 Trans & 700R4 so all I hav to do now it plug in the trans any time for the 700R4 and it's ready to go. Got the dist .
I don't remember what years started the computer controlled trannies but the 88 and newer 700r4's had a electronic speedo drive also. This is easy to swap over to a cable drive like you will need for your truck. Just find one from a 83-87 that was cable drive, rob the tail shaft and the gear drive off the output shaft and swap to the other. As far as making the lock up work, I have an article written in the 7004r section on how I wired mine up for 4th gear lock up only. This can be done with the tranny in or out of the truck. You will have to drain out the tranny fluid to do this also and is a fairly easy process to do. What year is the tranny you have?
[glow=blue,1,300][shadow=green,left,150] 86 1/2 ton 2wd Parts house replacement 350 Several performance parts added Performance built 700r4 4.11 gears with a true locker[/shadow][/glow]
Post by Pontiac1976 on Jun 14, 2007 21:23:55 GMT -5
Well I robbing the guts out of a rebuilt 94 1-ton van 8 month old paid $200. selling the case puting in a 82 case paid $100. I up grade it a little bit more. should cost me about 1200. to 2000 with the extra + taxes from the other trans. If not it would cost about 2800. & + up grades & taxes
Hello all. Fresh meat Kilo here. I see all of the threads here about this swap but I don't see anything pertaining to my application. Plain and simple. I know it can be done but what's needed to mate a 700R4 to my 454 in my `79 Chevy/GMC C35 Crew Cab. 8' bed dually, currently with a TH350? I see already what I have to do with the lock up by reading the rest of the post here.
Post by Pontiac1976 on Sept 23, 2008 22:58:44 GMT -5
Well it depeneds on what your truck has on it. Ie. 350 Motor and 350TH in a step side with a short shaft.Can be changed to a 454 Motor and 400TH with the same drive shaft 700R4 is all most the perfect match in length to a 400TH. The 700R4 when mounted has to sit on the cross member but the cross -memeber has to move back a set of holes. Because the mount is on the 700R4 is closer to the tail then the 400TH mount. You should need drive shaft that is one piece and out of a 6' box I beleave . But maybe a few others will jump in and to this topic
77 1/2 ton Heavy Half chev 454,350TH,3.07rear driven 6 YR now changed back to 85 monte carlo SS 305 Motor as of 2004, june,30 inter changed to 84 GMC style, flatbed with a 98 van bumper.