The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post

72seeten · 01-20-2007, 09:16 PM

I had a 700r4 that was modified w/ the check ball trick in a truck I used to own. It did not work very well at all. It lugged and had a rough operation. Then it broke. Had another tranny that I tried the vac switch/brakelight switch mod on the same truck, and it didn't work very well either. I finally ended up hooking it up through the ECM and it worked perfectly. (It was a 90 GMC that I converted from a 5spd to an auto) Since this one doesn't have an ECM (yet, I'm thinking about a TBI conversion) I was wondering if I could get away without it. I've heard different opinions, from numerous tranny shops, I was wondering if it is really necessary.

01-20-2007, 09:16 PM	#15
72seeten Junior Member Join Date: Nov 2006 Location: ATX Posts: 31	Re: What kind of posi unit is this? I had a 700r4 that was modified w/ the check ball trick in a truck I used to own. It did not work very well at all. It lugged and had a rough operation. Then it broke. Had another tranny that I tried the vac switch/brakelight switch mod on the same truck, and it didn't work very well either. I finally ended up hooking it up through the ECM and it worked perfectly. (It was a 90 GMC that I converted from a 5spd to an auto) Since this one doesn't have an ECM (yet, I'm thinking about a TBI conversion) I was wondering if I could get away without it. I've heard different opinions, from numerous tranny shops, I was wondering if it is really necessary. __________________ 1972 SWB