87 TBI to carb swap question

[2square]

Hey everyone, I have a 87 r10 that I'm restoring, I have replaced the stock 305 TBI with a 400 HP vortex 350 with a 750 demon carb I'm faking it until I make it here, but what do I need to do to the fuel system to make this work? I was planning on going with a mechanical pump, but am open to electric if it's easier/cheaper? Do I need to change the sending unit? Or install a regulator? Both? Any help is greatly appreciated.

 

[C10MixMaster]

Hey everyone, I have a 87 r10 that I'm restoring, I have replaced the stock 305 TBI with a 400 HP vortex 350 with a 750 demon carb I'm faking it until I make it here, but what do I need to do to the fuel system to make this work? I was planning on going with a mechanical pump, but am open to electric if it's easier/cheaper? Do I need to change the sending unit? Or install a regulator? Both? Any help is greatly appreciated.

the stock electric tbi pump in the tank wont supply enough fuel for 400 hp.
if you do a mechanical pump i would remove the in tank pump and replace it with a mechanical pump style sending unit or modify your sending to draw fuel from the bottom of the tank.
If you go electric you can upgrade the in tank pump (the ones used with vortec motors are suppose to be good to 450 hp ) and add a regulator for the carb. If you go electric you will need to modify your wiring seems to me the computer and oil pressure switch controlled the tbi fuel pump.

 

[2square]

Thanks for the help. I want to do this the right way... I've seen a few videos of guys simply installing a regulator on the stock fuel lines and not changing the sending unit, but like you said I'm not sure that would work with the added HP and 750 CFM carb? I've also seen a guy who just pulled the fuse for the existing fuel pump and Installed a mechanical fuel pump to the existing lines and claims it pulls fuel fine.but like I said I want to make sure I do this in a way that is effective/efficient. I'm leaning to installing a mechanical capable sending unit right to the carb... Seems like the simple solution. I like simple I'm planning on running this truck the simplest way if possible no computer I'm used to the older cars

 

[75gmck25]

Does your Vortec block have provisions for a mechanical pump? Many newer Vortec blocks are designed for EFI and are not set up for a mechanical pump.

Bruce

 

[Charlie]

 

[Frankenchevy]

Does your Vortec block have provisions for a mechanical pump? Many newer Vortec blocks are designed for EFI and are not set up for a mechanical pump.

Bruce

Ditto. My block looks like it has a mounting pad for a mech pump, but it isn’t drilled through. I’d assume no lobe either.

 

[2square]

Hey guys thanks for the warm welcome hah, my block does have the provisions to install a mech pump and the box of the truck is not bolted down at this point so I think the right thing to do is just go with the proper sending unit run some new 3/8 line, bobs you uncle. Most guys I've seen on the internet swapping to carb just use a regulator on the fire wall, but then I would need fittings and find the wire and I'm not sure what GPH the stock pump puts out, so being a simple guy I'll just do it the simple way. If I'm missing something let me know! Thanks everyone!

 

[Remo76C15]

Wow

 

[Remo76C15]

Wow

 

[CSFJ]

Wow

Wow

So impressive you had to say it twice?

 

[Rusty Nail]

Wtf?

 

[Rusty Nail]

Wtf?
That was weird..

 

[RangRayy]

When I did my efi to carb swap on my ‘87 I ditched all of the stock fuel system. I bought an in-line electric fuel pump that only puts out 4.5gph so no need for a regulator. Using a blazer tank mounted where the spare tire was, in-line pump and fuel line is all I have now.

 

[Rusty Nail]

"the RIGHT hole" lmao...

Got NE pix?

Hay! @RangRayy . Sup?