dragracer1586

In the process of building a 383 for my truck. Should be in the neighborhood
of 300 HP and have a stock TBI intake with a 454 tbi unit on there now and wanted to know if the stock fuel pump will support it if not what pump and what size injectors should I need?

UnderCover89TBI

iTrader: (25)

deffinately wanna do a fuel pump upgrade. TPI fuel pump should suffice. I think your underestimating the horsepower level of the 383. What heads are you using?

dragracer1586

Thanks for the reply! Can't remember the head number as there at the shop..I want to do just a little pocket porting to them to remove most of the casting under the valve..What's the part number for the TPI pump..
Also what is the general rule of thumb for the injectors as I see there are alot of different one's as per lb...Don't know much about all this TBI stuff so any help will be appreciated...THANKS!!!

Ok I found some notes that I had and looks like there 083 iron heads but not sure of the valve size. And think there 68cc chamber so I am using a dished piston in the -12 to -22 cc..

UnderCover89TBI

iTrader: (25)

i think for that build you might wanna use the 454 injectors. I am not good with that stuff.

and the ac delco tpi pump is ep241 but maybe the fuel volume wont be enough for a 383? someone else will hopefully chime in.

dragracer1586

Thanks Undercover but there is no one here that can answer my question about the injector's??? I see there was 3 or 4 different lb injectors for the 454 and I have a 454 TBI that I am going to use for this build but just wanted to know what one should be used..Thanks

xch3no2

17084327 stock 68#, use 35psi for your 383.

dragracer1586

Thanks xch, I will go with the TPI pump but what adjustable regulator kit
is the best to get? I see a lot of them on ebay. Does anyone here sell them that I can deal with??

xch3no2

Make yours adjustable, it's free.

dragracer1586

I like free....Is there a post here how to do it?? OK I will look around

UnderCover89TBI

iTrader: (25)

believe it is under the ultimate tbi mods in the sticky threads.

dragracer1586

I found some 80 and 90 lb injectors and how do I get 35psi with the regulator?
I know make it adjustable but does it need a different spring?
Thanks for the help guys

xch3no2

You found NO 90 lb injectors. They don't exist.

Whoever told you that is just ignorant.

Use the 94-95 bigblock spring, mentioned in this thread where the wrong injectors were used.

https://www.thirdgen.org/forums/tbi/...-pressure.html

dragracer1586

OK but this guy is advertizing them and has a set of 80lb on E-bay for sale..Will the 80lb be good?
Thanks for the help xch..

RBob

iTrader: (1)

Check the fuel pressure that they are rated at. Stock is 13 psi while others use 14.5 psi. Which makes that 90#/hr injector an 80.5#/hr injector at the rated 13 psi.

RBob.