LT-1 and 4L60E in a 70 swb - The 1947 - Present Chevrolet & GMC Truck Message Board Network

70cst10 · 06-10-2002, 11:06 AM

I've got a rolled over 95 z28 with about 90k on it. I want to put that in the 70 swb. I've been trying to list all of the things I would have to change to get it working. Does anythnig have to be done to the radiator? The lt-1 is reverse flow right? Can I get a factory tach to work? How about the mechanical speedometer? Will the rear end fit? I'd love to have discs and posi, but I want to make sure everything will fit right. Oh, what would I have to swap to use 73+ discs up front? Do I need the whole crossmember or can I just swap the spindles and control arms? So many questions.. I hope to have this thing down to the frame by the weekend, so I can start blasting it saturday!

My family thinks I'm nuts! Is it sick to have so much fun tearing things apart? I hope not!

red71cheyenne · 06-10-2002, 11:43 AM

The radiator won't matter if you use the same pump and water neck as the LT1. You will probably need a longer intake hose though, unless you want to do some re-engineering on the thermostat housing. You will have to move the tranny crossmember back 2" and bolt it there and shorten the drive shaft. Same output splines as a th350 though, so thats easy. You'll have to get a external fuel pump or change the tank out to one in the tank and reroute the lines. Tranny cooler lines will work, you just have to stretch them a little. The biggest problem I have found is the wiring situation. I've jury rigged mine with a newer fuse box and its not working the best. The engine and tranny work great but the wiring is hit and miss. You might be better off buying an aftermarket harness from Painless. I'm looking for one now. Either way, good luck and email me if you have any other questions. Jeff.

Big69C20 Toy · 06-10-2002, 12:38 PM

For the front end a 73+ truck spindles with disc will work. just gotta make sure you get the same balljoints for that year too. Often times i've heard the arms and all that front end stuff is all pretty worn so some guys just get the whole front but on mine i just used spindles, balljoints and outer tie rods. Best of luck with the conversion.

superchevy · 06-10-2002, 10:24 PM

contact Street & Performance in Mena, Arkansas at www.tunedport.com
They have everything you will need to do the swap.
SC

boilrman · 06-11-2002, 12:08 PM

There is not a mechanical connection for the speedo on the 4L60E trans. The trans is electronically controlled. It has a speed sensor on the tail, drivers side that senses speed and controls shifting.

I just changed out my 4L60E (rebuilt) in my 95 Astro van.

Stepside · 06-11-2002, 05:32 PM

http://www.abbott-tach.com/cablex.htm
There are ways around the speedo thing. I'm doing an Auto Meter dash, going with the electric speedo.

06-10-2002, 11:06 AM	#1
70cst10 Senior Member Join Date: Jun 2001 Location: Gaston, SC Posts: 580	LT-1 and 4L60E in a 70 swb I've got a rolled over 95 z28 with about 90k on it. I want to put that in the 70 swb. I've been trying to list all of the things I would have to change to get it working. Does anythnig have to be done to the radiator? The lt-1 is reverse flow right? Can I get a factory tach to work? How about the mechanical speedometer? Will the rear end fit? I'd love to have discs and posi, but I want to make sure everything will fit right. Oh, what would I have to swap to use 73+ discs up front? Do I need the whole crossmember or can I just swap the spindles and control arms? So many questions.. I hope to have this thing down to the frame by the weekend, so I can start blasting it saturday! My family thinks I'm nuts! Is it sick to have so much fun tearing things apart? I hope not! Attached Images __________________ Milan 1964 Chevelle SS 283/M20

06-10-2002, 11:43 AM	#2
red71cheyenne Back in the sticks Join Date: Jan 2001 Location: Fordland, MO Posts: 3,188	The radiator won't matter if you use the same pump and water neck as the LT1. You will probably need a longer intake hose though, unless you want to do some re-engineering on the thermostat housing. You will have to move the tranny crossmember back 2" and bolt it there and shorten the drive shaft. Same output splines as a th350 though, so thats easy. You'll have to get a external fuel pump or change the tank out to one in the tank and reroute the lines. Tranny cooler lines will work, you just have to stretch them a little. The biggest problem I have found is the wiring situation. I've jury rigged mine with a newer fuse box and its not working the best. The engine and tranny work great but the wiring is hit and miss. You might be better off buying an aftermarket harness from Painless. I'm looking for one now. Either way, good luck and email me if you have any other questions. Jeff. __________________ 1971 Cheyenne C-10 w/700R4 and Tuned Port Injection 1969 K5 Blazer w/Tuned Port 2010 2SS/RS Flaming Orange Camaro 2011 K1500 Suburban 2014 K1500 Pickup 2008 Nissan Altima? The wifes' hoopty

06-10-2002, 12:38 PM	#3
Big69C20 Toy Livin' it up. Join Date: Nov 2001 Location: Richland, MI Posts: 2,212	For the front end a 73+ truck spindles with disc will work. just gotta make sure you get the same balljoints for that year too. Often times i've heard the arms and all that front end stuff is all pretty worn so some guys just get the whole front but on mine i just used spindles, balljoints and outer tie rods. Best of luck with the conversion. __________________ -Greg; Sold the 69 C20. It's off to a better home with more love! Now onto the 86 CUCV M1009; K5 blazer with 6.2L diesel, corp 10 bolt axles, Detroit locker in the rear, trutrac front, 3.73 gears, 35" tires.

06-10-2002, 10:24 PM	#4
superchevy Got big-block? Join Date: Jul 2000 Location: Austin, Texas Posts: 2,453	contact Street & Performance in Mena, Arkansas at www.tunedport.com They have everything you will need to do the swap. SC __________________ '68 CST SWB factory 396/T400 buddy buckets, a/c, ps, pb '72 Corvette convertible 454/4spd/ac, ps, pb '73 GMC Sierra Grande short wide 454/T400 ps, pb, ac '77 K5 Blazer black on red, 350/T350/NP205 ps, pb, ac all original '78 GMC Sierra Classic short wide 454/T400 ps, pb, ac '72 GMC Sprint SP454. 1 of 38 built. '73 GMC Sprint SP454. 1 of 71 built. '75 GMC Sprint SP454. 1 of 25 built. SOLD! '72 GMC K25 4x4 468/4L80e/NP205 build thread http://67-72chevytrucks.com/vboard/s...23#post4324423 SOLD!'55 Chevy gasser 496/4spd build thread http://67-72chevytrucks.com/vboard/s...96#post4324396

06-11-2002, 12:08 PM	#5
boilrman 70 Chevy 3/4t Join Date: Sep 2000 Location: Kokomo,IN USA Posts: 1,230	There is not a mechanical connection for the speedo on the 4L60E trans. The trans is electronically controlled. It has a speed sensor on the tail, drivers side that senses speed and controls shifting. I just changed out my 4L60E (rebuilt) in my 95 Astro van. __________________ Find a job you love and you'll never have to work a day in your life. 1998 Yamaha V-Star 650 1970 Chevy 3/4t, I6 (rebuilt), 4 speed Kokomo,IN

06-11-2002, 05:32 PM	#6
Stepside Gasser Join Date: May 2000 Location: Thomasville,NC USA Posts: 456	http://www.abbott-tach.com/cablex.htm There are ways around the speedo thing. I'm doing an Auto Meter dash, going with the electric speedo. Attached Images __________________ :thud 70 sstep tubbed, Muncie, double hump, snowflake,



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