I know that if you put a carb vortec in a TBI car you need a fuel regulator. Im swapping a carbed vortec into my 87 Trans Am that was factory carbed. Do I still need a regulator? Is there anything specific I have to do to be without the mechanical pump? Thanks

 

Your 1987 car, if was factory carbed car, should have a mechanical fuel pump on the block, as well as an electric "helper" fuel pump in the tank. I'm guessing the Vortec motor doesn't have a fuel pump hole on the side of the block huh?

Might need to add another external electrical pump outside the tank, I'm not sure how capable the "helper" pump is in sending enough fuel to the front of the car. And you should have a return system, so you'd still have to use a return style fuel pressure regulator like the Malloory 4309 I'd think. But I'm no expert, just thinking out loud with ya - wai8t for better answers from someone more familiar with a 1987 carbed car and the "helper" pump in the tank.

 

I'm fairly sure the intank supply pump wont supply your vortec motor sufficient fuel. it was intended to prevent vapor lock in high temperatures. I would definitely install an electric pump to replace the mechanical OE unit.

 

I checked and the vortec we bought does have the machining for a mechanical fuel pump. I read something about the lobe on the cam for this? Is there anyway to tell?

 

Most cams had the lobe, whether or not they were installed in mech fuel pump applications. You could try installing the fuel pump push rod and see if it acts with rotation of the engine. If not, you'll have to change cams or go electric.

 

I checked and it doesnt have the lobe. Where can I find cams that do? Comp, Lunati?

 

Are you sure it has the fuel pump hole in the block? Even my early 90s truck block doesnt have functional mechanical fuel pump provisions.

you sure it's a Vortec block?

 

I am nearly positive. It has everything at the mechanical fuel pump part of the block as my stock 305 does. And thats compared side by side. Its an 880 block. It came out of a wrecked 96 Tahoe. I can completely put the push rod in the hole.

 

Basically, every cam manufacturer grinds the fuel pump lobe into even their EFI cams just so that its there in case an engine builder decides to use the cam in a carb application. Only GM would eliminate it cause their dumb like that. To be sure, ask the manufacturer of the cam you use. If you can install the push rod, you can install a mechanical pump.

 

Thanks, thats exactly what I needed to know. On another note, to save another thread; what work is needed on stock vortecs to handle higher lift in the .500 range or so?

 

I haven't really messed with Vortec heads much. From what I gather, the key issue is valve guide to retainer clearance and machining spring pockets for decent springs. A good head shop will help you greatly in this regard. Just tell them what your cam specs are and they will set the heads up for you.