I am switching from a TPI 350 to a TBI 350 and need to know if I need to get a different fuel pump or will the fuel pump that is already in there for the TPI will work for the new TBI system.

TPI needs about 50 psi, TBI needs about 12-15.

I am switching from a TPI 350 to a TBI 350 and need to know if I need to get a different fuel pump or will the fuel pump that is already in there for the TPI will work for the new TBI system.

depending on the sending unit you are using, you can get a walbro pump for about 110$ that will fit like stock and is 255 lph and 100 psi. lemme see what i got from summit...

http://store.summitracing.com/partdetail.asp?autofilter=1&part=EDL%2D3581&N=700+0&autoview=sku thats the one i got for my blazer with the vortec swap. should work fine on a tpi.

depending on the sending unit you are using, you can get a walbro pump for about 110$ that will fit like stock and is 255 lph and 100 psi. lemme see what i got from summit...

http://store.summitracing.com/partdetail.asp?autofilter=1&part=EDL%2D3581&N=700+0&autoview=sku thats the one i got for my blazer with the vortec swap. should work fine on a tpi.

No, he's going the other way.



Why are you ditching TPI?

The pump makes no difference as long as it produces enough pressure.
The regulator is in the throttlebody not in the pump.

The inline pumps I recommend will produce 95psi.
But the regulator maintains the required 13psi for TBI.

I recommend you spend a lot more time reading the FAQ in the injection forum in my sig.

BTW, the type of ign switch has nothing to do with wiring a FI system!!

Why are you ditching TPI?

The motor that was in with the TPI had a really bad squel and a small knock, I got a deal on a FREE TBI that was put into a truck new about two years ago, the truck got wrecked, the motor has only about 12000 miles on it and is in perfect condition.


Thanks BILL or the info that is what I was hoping to hear. Will defintley check the links in your sig thanks.

Why don't you put the TPI stuff (heads, and injection) on the TBI block? It should all bolt on with no problem.
The TPI block is roller cam/lifters, with good heads while the TBI block is most probably low performance heads and a flat tappet cam.
I tried using my stock Jeep 4.0L in-tank pump to run my TBI. The regulator would not reduce the pressur adequately, causing the engine to run way rich. I was forced to install a stock TBI pump.

Pilot... you really want to keep your TPI system. It doesn't make sense to go back to a TBI from a TPI.

I am not going from tpi back to tbi I am changing motors completely.
yeah I thought about swapping the tpi stuff onto the tbi block, but I thought that I would just leave the TBI motor all together, especially since it is such a "new" motor with only about 12000 miles on it.

I hate to gang up on ya. But I have to agree with everyone else. TPI is about 100 times better than TBI. IMO take the time to swap the TPI parts onto your new engine. You will thank us later.

all you have to do is swap manifolds. not like you got to pull the heads or crank... lol.

Unless your TPI engine is very early ,( with center 2 bolts at the same angle as the other 4 on each side) , your TBI mani will bolt straight on with no probs .If you do have early mani , I've had good luck using a 3/8 drill bit and hand machining the bolt holes to match later heads and then making tapered washers to match mani .

Also switch knock sensor or sensors . If you have aluminum heads on the TPI eng , switch em to TBI block .

In the stock chevy fuel pump pick up ,a stock TPI or TBI pump will simply interchange .

IMO ,a gasket kit is about same price as a cheap fuel pump , or even cheaper , and TPI engine power is worth more then a couple of hours changing heads to retain TPI ,and all 100% of TPI wiring will have to be changed ,also.

Corvette engine always sounds cooler .