tbi to carbed swap info needed

[shortchevy]

ok heres what Im planning on doing. i got a 91 GMC that needs a motor (blown head gasket, fractured ring, possible cracked block, and 215k miles) I picked up a 350 that I believe is out of an early 70s chevy pickup. the motor is carbed with a cast intake and a quadrajet.... Im gonna be running the stock trans from the 91 since it feels like it has been rebuilt recently. I already know about the fuel pressure issues, I plan on snipping the wires to the expensive stock unit and just using the mechanical pump on the replacement motor. I know I will have to hook up the distributor to an ign. hot source. the trans is easy, its a 91 so that tells me its a 700r4 so I just have to hook up the corresponding vacuum/kickdown lines. vacuum lines, throttle cables ect.... Im getting new oil, filter, coolant, and exhaust manifold gaskets.... Im getting a motor from a family friend that I know runs very well so im not worried about that. Im just making sure i am not missing anything. anyone who has done this swap please let me know if I got it all covered.
thanks in advanced
Pete

 

[Tempted]

Why snip the wires on the pump? It is a low pressure pump, 12psi. Toss a FPR on it, drop to 8-10 and let her ride.

 

[shortchevy]

Why snip the wires on the pump? It is a low pressure pump, 12psi. Toss a FPR on it, drop to 8-10 and let her ride.

I also thought of this... I looked at regulators and theyre expensive. the mechanical pump would be free. if the pump ever fails it will be tons cheaper and easier to replace the mechanical pump.

 

[Tempted]

Go ahead and pull the pump out then. It really isn't hard, 8 bolts on the bed, a couple tail lights and an engine hoist. But leaving it is gonna leave you a pinch point in the system. Most of the regulators I've used for low pressure systems were well under a hundred bucks. You can get cheapos at the local parts house for around 20. I like them because they don't take any engine revolutions to get pressure in the lines.

 

[shortchevy]

Go ahead and pull the pump out then. It really isn't hard, 8 bolts on the bed, a couple tail lights and an engine hoist. But leaving it is gonna leave you a pinch point in the system. Most of the regulators I've used for low pressure systems were well under a hundred bucks. You can get cheapos at the local parts house for around 20. I like them because they don't take any engine revolutions to get pressure in the lines.

the fpr i was looking at was so expensive because it had a return line... could I cap the return and use a cheaper fpr then?.... pulling the stock pump isnt a problem. this is a super low buck swap and getting rid of something is usually cheaper than adding stuff. as far as pulling the bed, that aint happening to me on an OBS ever again, get the cuttin' wheel were puttin a hole in er! haha. thanks a bunch for the advice, if I wasnt so cheap I would take your advice for sure, because what your suggesting is the proper way to hook this up.

 

[MOBS]

Other than your manual or electric with fpr decision.........looks like ya got everything figured out. Are you planning to use the same sensor hookups, like for your oil pressure, temp gauge, etc? Since you're going with a quadrajet engine, ya might as well throw a cam in there. 70's chevy truck motor right? Should be 73cc chamber heads, so don't go too big in cam selection.

 

[shortchevy]

well went and pulled my motor out of a buddies 67 chevelle today. Its looking like an 80s 350, my only reasoning is that its a black block... ran it for a while before pulling it to see how it ran. ran strong, sounded good, had a bad fan clutch but I will be using my fan.... ive decided to go with the mech pump because the one on the new block is brand new, it would hurt to not use it. now were waiting for another nice weekend to slap er in!

 

[shortchevy]

over the last couple weeks I got the swap done... I did the swap at my dads house which is about 45min away so I really only got to work on it 2 hours at a time.... for anyone else doing this swap here are my notes....

-If you just pull the fuel pump relay and fuse you will loose your fuel gauge. snip pump wires
-If you are running a mechanical fuel pump like I am you have to either install the motor mount bolts before the pump or install the passenger side bolt from the back
-If you are using your stock accessories and serp setup you need to use a reverse rotation water pump.
-I blocked off the heater hose location on the rad and used the locations from the chevelle motor (water pump and front of intake)
-12volt ignition hot wire for the HEI
-12volt ignition hot wire for choke
-the Chevelle that I got the motor out of had a different throttle cable/trans kickdown bracket so I had to go grab one out of the junkyard


all in all it wasnt a bad swap... I have a few little kinks to work out but its all in and runs strong.

 

[Swims350]

I don't know why you lost the fuel gauge. I had an 85 monte carlo that was 4.3 tbi and it had the in tank pump and wires, they just removed the computer, relays and left it as is, my fuel gauge worked fine.

 

[shortchevy]

I don't know why you lost the fuel gauge. I had an 85 monte carlo that was 4.3 tbi and it had the in tank pump and wires, they just removed the computer, relays and left it as is, my fuel gauge worked fine.

I would love it if my gauge worked! let me get back to you on this one tomorrow when I make a gas station stop. I know it was near empty when we started but Im not sure how empty and when I got it going today it was all the way down. Ill post tomorrow what I find out