94 K1500 TBI / Vortec head swap - Cam question

**Roadknee** · 10-22-2015

Originally Posted by dispoejoe95

Another question...I'm trying to determine if I will need a fuel pump. When checking fuel pressure, does it matter where in line you hook up the gauge? I put the fitting in line right behind filter (between the filter & the tank)...it was the easiest place to gain access. To my surprise it was 18psi at idle with the regulator adjusted all the up. To the best of my knowledge this is the stock pump. I'm the 2nd owner and I've had this truck since 2001.

I prefer to check by the throttle body. But unless your filter is plugged you should be close. 18 psi with a stock spring makes me think the spring may be bottomed out. You'll need a stiffer spring for at least 22 psi with stock injectors for the vortec headed 350. I'd also recommend you upgrade to the EP377 fuel pump.

For tuning I'd recommend an emulator so you don't have to pull the ECM each time you burn a new tune to change chips. I use the Autoprom from www.moates.net. When I'm done tuning, I can burn a chip with the Autoprom, install the chip and remove the Autoprom from the truck.

**dispoejoe95** · 10-23-2015

Originally Posted by Roadknee

I prefer to check by the throttle body. But unless your filter is plugged you should be close. 18 psi with a stock spring makes me think the spring may be bottomed out. You'll need a stiffer spring for at least 22 psi with stock injectors for the vortec headed 350. I'd also recommend you upgrade to the EP377 fuel pump.

For tuning I'd recommend an emulator so you don't have to pull the ECM each time you burn a new tune to change chips. I use the Autoprom from www.moates.net. When I'm done tuning, I can burn a chip with the Autoprom, install the chip and remove the Autoprom from the truck.

Thanks Roadknee. Does the EP377 fit into the stock TBI sending unit or will I need to make some modifications? What about the EP381?

**buddrow** · 10-23-2015

Originally Posted by dispoejoe95

Thanks Roadknee. Does the EP377 fit into the stock TBI sending unit or will I need to make some modifications? What about the EP381?

I believe the EP377 is the TPI fuel pump, which hangs in the tank just like the one in your truck if it's pre '98.

Buddrow

**Roadknee** · 10-23-2015

Originally Posted by dispoejoe95

Thanks Roadknee. Does the EP377 fit into the stock TBI sending unit or will I need to make some modifications? What about the EP381?

The EP377 is the '95 454 TBI pump rated 30 psi. The EP381 is the vortec 350 pump rated around 60 psi. I prefer the 377 because it will be operating at closer to its rated pressure. Either will drop into the stock truck sending unit.