Big Throttle Body upgrade (Holley)

[tirefryer93]

Ok, I finally finished my Holley 670cfm conversion on my 1993 chevy 355. Holley makes these throttle bodies for 87-89 pickups, but the only difference is the TPS hookup. If anyone else has been wondering about the Holley on a newer 350 TBI, go for it. As I stated before in another thread, the TPS hookup is different on the newer 350s. But fortunately, the TPS clip (older style) is the same on 4.3s, 305, and 350s. So I took one off a 4.3 caprice. The wires (3) are color coded, so it is simply a cut-and-splice operation. The Holley also comes with wires that go to the injectors, but that is another simple project. One thing to consider, however, is the fact that the Holley's "adjustable" fuel pressure regulator is not very adjustable. The screw is so tight that it won't budge, and it's maxed out at 10psi (I have a gauge set up on mine). But upon looking at the Holley further, I realized that I could use a regular adjustable fuel pressure regulator for the stock TBIs. It simply bolts on top of the unit opposite the way the oem canister is. So, to sum everything up, I went from a stock throttle body ( 420 cfm, 55# injectors, 11 p.s.i. ) to the upgraded Holley ( 670 cfm, 68# injectors, 15 p.s.i. ). I am telling you right now, if you want more power, do this upgrade!

[Tall]

So...can u watch the gas gauge drop at idle, or do you have to hit the gas pedal to make the needle slide over to the E?

[Silverado Brethern]

Sounds cool...so this cost how much? And is this available for my engine?

[flair666369]

TO: SILVERADO BRETHERN

Yes, bbk makes an 80mm throttlebody part number 1710 found for $350 give or take depending on which website your at. There are smaller ones out there, i forget which site i've seen them on, but the bbk is the biggest one i've ever seen. i personally don't have one yet, but i've heard that it helps low end power and throttle response alot. i have done alot of searching on the web, if your looking for any other performance parts for your truck, let me know, i think i've researched just about all of them.

Currently driving 98 GMC Z-71.

[Silverado Brethern]

Yeh i've seen the bbk tb's but im not in the mood to spend all that much right at the moment. And also if we get all these mods to increase the amount of air intake it would only seem logical to upgrade the fuel injectors, which are also rather pricy.

[tirefryer93]

I bought the throttle body on an ebay auction for $160. When I was finished with the project, I took the truck on a trip (about 300 miles) and got about 20 miles to the gallon. No complaints here.

[Silverado Brethern]

Well i was refer to higher flow injectors for more power, which would lessen mpg which is the last of my concerns.

[big_blue_chevy2006]

well holley now makes the 670cfm tbi for the 90 to 95 engines BUT one problem from jegs its very expensive 510 bucks exp. considering how the others only around 350 bucks