TBI Question

[lamogo33]

I'm in need of a Throttle Body for a 94 7.4l pickup and can't seem to find one reasonably priced. I think many people are taking them and selling them as performance upgrades to people with small blocks. I have come across the Holley 502-6 which flows 670cfm, but says it too is for a small block. Will it work for my application? I have a 92 Chevy 5.7l but have put in a 94 7.4l. I have the 454 wiring harness and computer I still need to swap over but need a throttle body to do it as that didn't seem to come with my engine when I bought it.

Here is a ling to an ebay as I'm considering.
Holley 502-6

 

[chipskittles]

Never heard anything good about the holley

 

[lamogo33]

Never heard anything good about the holley

Thanks, I guess I'll keep looking.

 

[someotherguy]

Use car-part.com and look one up. There are more than a few on there; I searched using a 1994 C3500 but of course 2500's had the 7.4 as well.

Something you should be keeping in mind as well is that the 1994-1995 7.4 runs at higher fuel pressure (range of 26-32 psi) so the injectors are different, as well as the fuel pump. Regulator inside the TBI is likely different as well (but I've never checked.) The earlier years run the same pressure as all the small block TBI's (around 9-13 psi)

If it was me, I'd probably buy the 1994-1995 TBI unit to keep the engine "all 1994" so you never get mixed up about what parts to buy, and pick up a new 1994-1995 fuel pump and put it on your 1992 sender.

If wondering about which year to use, TPS connectors changed on the small block in 1991, not 100% sure if big blocks followed that same year change but am reasonably sure they did. Something to think about anyway since it sounds like you have the 1994 engine harness in there.

Richard

 

[Big D]

I had mine rebuilt and modified through this guy http://www.sprperformance.com/ he is very knowledgeable about them and was very cool to talk to. He may have cores laying around.

 

[95Escahoe]

I had mine rebuilt and modified through this guy http://www.sprperformance.com/ he is very knowledgeable about them and was very cool to talk to. He may have cores laying around.

X2 on this when I had my OBS he did mine too


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[lamogo33]

Use car-part.com and look one up. There are more than a few on there; I searched using a 1994 C3500 but of course 2500's had the 7.4 as well.

Something you should be keeping in mind as well is that the 1994-1995 7.4 runs at higher fuel pressure (range of 26-32 psi) so the injectors are different, as well as the fuel pump. Regulator inside the TBI is likely different as well (but I've never checked.) The earlier years run the same pressure as all the small block TBI's (around 9-13 psi)

If it was me, I'd probably buy the 1994-1995 TBI unit to keep the engine "all 1994" so you never get mixed up about what parts to buy, and pick up a new 1994-1995 fuel pump and put it on your 1992 sender.

If wondering about which year to use, TPS connectors changed on the small block in 1991, not 100% sure if big blocks followed that same year change but am reasonably sure they did. Something to think about anyway since it sounds like you have the 1994 engine harness in there.

Richard

Thanks. Never knew that website existed. I was using ebay.

I also noticed about the fuel pump thing as well and intend to swap it out when its time. I have to do little by little here, and not having a wrecking yard within 100 miles from here makes it costly and slow. I have the engine running on the 92 computer, harness, and TB but she wont idle once she gets to about 100* water temp. As soon as I find a TB for a 94, I'll swap computers, and harness and pump, and hopefully have it running and idling better. Thanks for the help again.

 

[gmcyukondriver]

Check Craigslist. In CA, there's TONS of these trucks being parted out all the time. If you want a wider search area, use Adhuntr.com
I would search for 7.4 chevy part out, and see what comes up. That's how I found my Whipple in Arizona. Of course, shipping on a TB unit would be cheaper than I paid to ship this thing, but I won't get into that.

 

[TylerZ281500]

ive got all mine off craigslist, selling a few of the ones i have on there too