serious about the 700R4 Conversion - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Jason915 · 11-15-2006, 01:09 PM

I have read and re read everything in the FAQ section about the TH350 to 700R4 conversion and am really thinking about doing the swap. I have a parts list together and am going to start collecting the parts soon. I am thinking of sliding the motor forward a bit to compensate for the longer tranny besides I hate that it's so hard to get the last bolt in the header started so I don't mind moving the engine and saving the cost of driveshaft modifications.

Please if you have done this conversion let me know everything. I am looking for specific information about this conversion in the 1969-1972 K5/K10 body.

I really want the low first gear and the lock up torque converter along with OD that you get with this conversion.

Thanks

pharcyde05 · 11-15-2006, 01:19 PM

I am putting one in a 72 pick up right now so far havent came across any complacations will be sending drive line off next week

gringoloco · 11-15-2006, 10:35 PM

Very straight-forward install. Move crossmember back, shorten driveshaft, connect TV cable, enjoy.

roj2323 · 11-15-2006, 10:45 PM

the shift linkage is a pain be prepaired to do some head scratching.
ondrew

Chris27 · 11-16-2006, 10:25 AM

Here's what I did for my conversion.
AA output shaft, Moved engine ahead 1-3/4", Stock shift linkage on frame moved ahead approx 1" to line up with tranny, Stock cooler lines fit, Brake switch from 87' Suburban to unlock converter. For lockup control there are a few options, ECM or vacuum switch. I have done both. They operate the same, except the lockup only works in OD with the vacuum switch. ECM also locks up in 3rd. I see you have TBI so your wiring harness should already have the proper connecters for this. Make sure you run a VSS (vehicle speed sensor) & have an accurate speedo, or the ECM won't know when to lock & unlock the converter. I have a VSS that retains the stock cable drive speedo as well. Be sure to get TV cable & brackets from the same vehicle ,as there are a few different lengths.

Chris27 · 11-16-2006, 10:34 AM

Oh yeah, and a neutral safety switch from the 'Burb as well. The stock one will work, but don't expect your back-up lights to come on when they should. Mine came on in neutral with the stock switch in place. Make sure to get a 'K' case 700R4 with the cast aluminum inspection cover. If you don't have the tranny yet, a good source is 87-91 S-trucks with the 4.3. They have the same tranny as the V-8 full size trucks and there are thousands of these in the junkyard ripe for pluckin'

AesC10s · 11-16-2006, 02:09 PM

dont put to much power in front of it. i have 325hp 350 and blew mine to peices....

71chevylowrider · 11-16-2006, 02:15 PM

Hey AesC10S, was your 700R4 built up for your application? Or did you pluck one from a junkyard & take your chances? I'm planning my 700R4 upgrade & looking for the best/cheapest option without having to keep putting tranny's in it.

AesC10s · 11-16-2006, 02:16 PM

mine was out of a stock 85 carmaro i had layin around.

71chevylowrider · 11-16-2006, 02:33 PM

Yea, I'm worried about throwing a used one in there & crossing my fingers, I'm always "testing" when i take a "spin" in my truck, I don't want to have to baby it, my TH350 has a shift kit & works great, it has no problem laying rubber when it downshifts into second at 30MPH.

AesC10s · 11-16-2006, 02:35 PM

Quote:

Originally Posted by 71chevylowrider

Yea, I'm worried about throwing a used one in there & crossing my fingers, I'm always "testing" when i take a "spin" in my truck, I don't want to have to baby it, my TH350 has a shift kit & works great, it has no problem laying rubber when it downshifts into second at 30MPH.

Nise, what motor you running.

71chevylowrider · 11-16-2006, 02:55 PM

Um....this one it's a 350 mildly massaged.

Actually the previous owner had this truck & pumped loads of money into it for over 18 years, & I can't get all the data on the motor, (he forgot alot of stuff, like what cam is that?) it is very healthy though,he can't remember if it'a an isky, or a lunati, or a comp, crane or what it has a very lumpy cam, ceramic coated Hooker Headers, Roller rockers, edelbrock RPM ect. , soon to have a Road Demon Carb, the truck has $3500 worth of stereo equipment in it & I rarely turn it on, I love that buh,blubabuhblubba,buhblubbaba sound when it's idling. it has alot of good parts on it though, I would imagine it's in the 350HP range

AesC10s · 11-16-2006, 03:14 PM

That is a good looking motor. i was also told haveing a 700r4 built wont do ya much better.the trannys are just weak i guess.

67ChevyRedneck · 11-16-2006, 03:35 PM

Quote:

Originally Posted by AesC10s

mine was out of a stock 85 carmaro i had layin around.

Unless it was an IROC I think all camaros (even Z28's) back in 85 only had a weak 305 in them, also if you did the swap recently, that's a 20 year old used automatic......

I have a 700R4 in my truck. I got a TV made EZ and lock-up kits from Bowtie Overdrives. These kits are a must (especially the TV cable kit) becuase you WILL BLOW a 700R4 with an improperly adjusted TV cable. They are not as simple as bolt on bracket and adjust by "feel."

Bowtieoverdrives.com has some great info.

Chris27 · 11-16-2006, 04:02 PM

If you build 'em right and have the TV set properly they will handle alot of power. My '69 Beaumont has a 388 stroker small block making 479HP & 472 lbs.Ft. of tourque and has been in the car for 5 years with about 200+ dragstrip passes (12.03 @ 113 MPH) and 20,000 street miles on it. I'm not worried about the tranny in my K5 behind a stock TBI 350.

71chevylowrider · 11-16-2006, 05:27 PM

Hey Chris, it sounds like you know these pretty well, did you build it? If so....what parts/kits do we need to but to make these things bullet proof? I wouldn't mind buying one chaep off of a S-10 & then having some one put the right parts in it.

Chris27 · 11-16-2006, 07:14 PM

Both my 700R4s got Kevlar bands and clutches, shift kits (real harsh one in the car, "soft" one in the blazer) A local guy built both of them for me. other than that the're basically a stock rebuild. And the biggest tranny cooler I could find on both of them. Heat is any automatics worst enemy. The car will bark the tires into 3rd gear (on slicks) and the truck shifts quik but not too hard. Towing in OD is also a big no-no. I generally cruise around town in 3rd gear and only use OD on the highway. With the tranny in 3rd, line pressure is boosted compared to running around in OD.

71chevylowrider · 11-16-2006, 07:32 PM

sounds cool, thanks for the good info, I can't wait to be able to purr on the freeway, right now the truck is quick, runs & rides great, but......on the freeway I'm at 3,500RPM's at 65MPH
won't be going on any trips too far till I get the 700R4

11-15-2006, 01:09 PM	#1
Jason915 Registered User Join Date: Jan 2005 Location: Colorado Springs Posts: 693	serious about the 700R4 Conversion I have read and re read everything in the FAQ section about the TH350 to 700R4 conversion and am really thinking about doing the swap. I have a parts list together and am going to start collecting the parts soon. I am thinking of sliding the motor forward a bit to compensate for the longer tranny besides I hate that it's so hard to get the last bolt in the header started so I don't mind moving the engine and saving the cost of driveshaft modifications. Please if you have done this conversion let me know everything. I am looking for specific information about this conversion in the 1969-1972 K5/K10 body. I really want the low first gear and the lock up torque converter along with OD that you get with this conversion. Thanks __________________ 1971 GMC K1500 SWB Fleetside, 4" skyjacker softride and, 14 Bolt FF, HD Dana 44 4.10's 1970 K5 TBI conversion lifted etc SOLD 1968 C20 camper truck SOLD “To ban guns because criminals use them is to tell the innocent and law-abiding that their rights and liberties depend not on their own conduct, but on the conduct of the guilty and the lawless.” Jeff Snyder

11-15-2006, 01:19 PM	#2
pharcyde05 Senior Member Join Date: Mar 2006 Location: modesto CA Posts: 239	Re: serious about the 700R4 Conversion I am putting one in a 72 pick up right now so far havent came across any complacations will be sending drive line off next week __________________ http://www.cardomain.com/ride/2461088

11-15-2006, 10:35 PM	#3
gringoloco A guy with a truck Join Date: Sep 2005 Location: Germany, for now Posts: 5,920	Re: serious about the 700R4 Conversion Very straight-forward install. Move crossmember back, shorten driveshaft, connect TV cable, enjoy. __________________ -Chris Instagram _elgringoloco_ '70 Short-Wide How to: Ruin a perfectly good C10 ‘70 Blazer ConversionHow To: Ruin a Perfectly Good 4wd '72 Highlander How To: Ruin a Perfectly Good K/5 (SOLD) '72 Blazer 2WD How to: Ruin a perfectly good Blazer (SOLD) '05 Yukon Daily Driven (not so stock) Yukon (SOLD) ‘07 Yukon Denali (daily) Members met list: SCOTI, darkhorse970, 67cheby, 67cheby'sGirl, klmore, porterbuilt, n2billet, Fastrucken, classicchev, Col Clank, GSFMECH, HuggerCST, Spray-Bomb, BACKYARD88, 5150, fine69, fatbass, smbrouss70, 65StreetCruiser, GAc10boy

11-15-2006, 10:45 PM	#4
roj2323 Senior Member Join Date: Mar 2004 Location: Somewhere Posts: 985	Re: serious about the 700R4 Conversion the shift linkage is a pain be prepaired to do some head scratching. ondrew

11-16-2006, 10:25 AM	#5
Chris27 Blazerless Join Date: Nov 2006 Location: Kelowna, BC, Canada Posts: 274	Re: serious about the 700R4 Conversion Here's what I did for my conversion. AA output shaft, Moved engine ahead 1-3/4", Stock shift linkage on frame moved ahead approx 1" to line up with tranny, Stock cooler lines fit, Brake switch from 87' Suburban to unlock converter. For lockup control there are a few options, ECM or vacuum switch. I have done both. They operate the same, except the lockup only works in OD with the vacuum switch. ECM also locks up in 3rd. I see you have TBI so your wiring harness should already have the proper connecters for this. Make sure you run a VSS (vehicle speed sensor) & have an accurate speedo, or the ECM won't know when to lock & unlock the converter. I have a VSS that retains the stock cable drive speedo as well. Be sure to get TV cable & brackets from the same vehicle ,as there are a few different lengths.

11-16-2006, 10:34 AM	#6
Chris27 Blazerless Join Date: Nov 2006 Location: Kelowna, BC, Canada Posts: 274	Re: serious about the 700R4 Conversion Oh yeah, and a neutral safety switch from the 'Burb as well. The stock one will work, but don't expect your back-up lights to come on when they should. Mine came on in neutral with the stock switch in place. Make sure to get a 'K' case 700R4 with the cast aluminum inspection cover. If you don't have the tranny yet, a good source is 87-91 S-trucks with the 4.3. They have the same tranny as the V-8 full size trucks and there are thousands of these in the junkyard ripe for pluckin'

11-16-2006, 02:09 PM	#7
AesC10s Chevy truck addict Join Date: Apr 2005 Location: Thornton Colorado Posts: 825	Re: serious about the 700R4 Conversion dont put to much power in front of it. i have 325hp 350 and blew mine to peices....

11-16-2006, 02:15 PM	#8
71chevylowrider Senior Member Join Date: Sep 2006 Location: Vancouver, WA Posts: 1,015	Re: serious about the 700R4 Conversion Hey AesC10S, was your 700R4 built up for your application? Or did you pluck one from a junkyard & take your chances? I'm planning my 700R4 upgrade & looking for the best/cheapest option without having to keep putting tranny's in it.

11-16-2006, 02:16 PM	#9
AesC10s Chevy truck addict Join Date: Apr 2005 Location: Thornton Colorado Posts: 825	Re: serious about the 700R4 Conversion mine was out of a stock 85 carmaro i had layin around.

11-16-2006, 02:33 PM	#10
71chevylowrider Senior Member Join Date: Sep 2006 Location: Vancouver, WA Posts: 1,015	Re: serious about the 700R4 Conversion Yea, I'm worried about throwing a used one in there & crossing my fingers, I'm always "testing" when i take a "spin" in my truck, I don't want to have to baby it, my TH350 has a shift kit & works great, it has no problem laying rubber when it downshifts into second at 30MPH.

11-16-2006, 02:55 PM	#12
71chevylowrider Senior Member Join Date: Sep 2006 Location: Vancouver, WA Posts: 1,015	Re: serious about the 700R4 Conversion Um....this one it's a 350 mildly massaged. Actually the previous owner had this truck & pumped loads of money into it for over 18 years, & I can't get all the data on the motor, (he forgot alot of stuff, like what cam is that?) it is very healthy though,he can't remember if it'a an isky, or a lunati, or a comp, crane or what it has a very lumpy cam, ceramic coated Hooker Headers, Roller rockers, edelbrock RPM ect. , soon to have a Road Demon Carb, the truck has $3500 worth of stereo equipment in it & I rarely turn it on, I love that buh,blubabuhblubba,buhblubbaba sound when it's idling. it has alot of good parts on it though, I would imagine it's in the 350HP range Attached Images

11-16-2006, 03:14 PM	#13
AesC10s Chevy truck addict Join Date: Apr 2005 Location: Thornton Colorado Posts: 825	Re: serious about the 700R4 Conversion That is a good looking motor. i was also told haveing a 700r4 built wont do ya much better.the trannys are just weak i guess.

11-16-2006, 04:02 PM	#15
Chris27 Blazerless Join Date: Nov 2006 Location: Kelowna, BC, Canada Posts: 274	Re: serious about the 700R4 Conversion If you build 'em right and have the TV set properly they will handle alot of power. My '69 Beaumont has a 388 stroker small block making 479HP & 472 lbs.Ft. of tourque and has been in the car for 5 years with about 200+ dragstrip passes (12.03 @ 113 MPH) and 20,000 street miles on it. I'm not worried about the tranny in my K5 behind a stock TBI 350.

11-16-2006, 05:27 PM	#16
71chevylowrider Senior Member Join Date: Sep 2006 Location: Vancouver, WA Posts: 1,015	Re: serious about the 700R4 Conversion Hey Chris, it sounds like you know these pretty well, did you build it? If so....what parts/kits do we need to but to make these things bullet proof? I wouldn't mind buying one chaep off of a S-10 & then having some one put the right parts in it.

11-16-2006, 07:14 PM	#17
Chris27 Blazerless Join Date: Nov 2006 Location: Kelowna, BC, Canada Posts: 274	Re: serious about the 700R4 Conversion Both my 700R4s got Kevlar bands and clutches, shift kits (real harsh one in the car, "soft" one in the blazer) A local guy built both of them for me. other than that the're basically a stock rebuild. And the biggest tranny cooler I could find on both of them. Heat is any automatics worst enemy. The car will bark the tires into 3rd gear (on slicks) and the truck shifts quik but not too hard. Towing in OD is also a big no-no. I generally cruise around town in 3rd gear and only use OD on the highway. With the tranny in 3rd, line pressure is boosted compared to running around in OD.



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11-16-2006, 07:32 PM	#18
71chevylowrider Senior Member Join Date: Sep 2006 Location: Vancouver, WA Posts: 1,015	Re: serious about the 700R4 Conversion sounds cool, thanks for the good info, I can't wait to be able to purr on the freeway, right now the truck is quick, runs & rides great, but......on the freeway I'm at 3,500RPM's at 65MPH won't be going on any trips too far till I get the 700R4

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