1988 C1500 carb conversion
 

I'm still in the hunt for a C1500. I would not keep the TBI on what ever I buy.
Any tips on converting to carb from TBI?
Also it seems like most C1500 have 400 turbos. Has anyone used a Gear Vendors OD unit?

Re: 1988 C1500 carb conversion
 

folks I know, just change the intake, add the carb, and re do the fuel pump. Not sure how the one guy redid the stock fuel pump. I know you'll need a regulator to lower the pressure. I don't remember the details and the guy is no longer around.

Far as I know, all the 1/2 ton C1500s had a 4l60 or 4l60E. I have only seen the T400 on the 2500/3500 models.

Re: 1988 C1500 carb conversion
 

Thanks for the reply. I haven't bought anything yet. One I'm considering a 1988 clearly states it is all original with a 400 turbo. May have been switched out from the 4L60E.
Just trying to the proper research.

Re: 1988 C1500 carb conversion
 

Most had the 4L60, many had the 400. '93 was the first year of the 4L60E.

Re: 1988 C1500 carb conversion
 

Yeah, I was surprised to learn not all these trucks had overdrive. I assumed they all did since they were so modern when they came out and overdrive became the standard in the '80s.

Re: 1988 C1500 carb conversion
 

TBI is a very simple and great working system. IMO it's silly to go through any work reverting to a carbed setup.

BUT....if you must, the little Mr.Gasket 12s inline fuel pump does not need a FPR and will normally suck the fuel straight through the existing in-tank pump so you don't even have to drop the fuel tank. You can also buy a carb to TBI adapter so you don't have to change the intaake.

Re: 1988 C1500 carb conversion
 

The truck I'm considering has a stock 305. I would be deleting the 305 and adding a 383/396 stroker. The TBI would not begin to support an engine of that size. I wonder about the control of the fuel pump. I assume it's controlled by the ECM like an LS. Does the stock ECM control anything besides the engine?

Re: 1988 C1500 carb conversion
 

It controls torque converter lockup.

Re: 1988 C1500 carb conversion
 

I'd never swap from TBI unless the engine puts out more than 450 HP.

https://harristuning.com/Tbi/

Re: 1988 C1500 carb conversion
 

Sure it will. Lots of guys running hot 383's on an almost stock TBI setup. I believe it's common practice to swap out to 454 injection and add an adjustable FPR to crank the pressure up a little bit. Then just get aa custom PROM. Easy Peasy:metal:

Re: 1988 C1500 carb conversion
 

Thanks again or the replies. As far as I know a turbo 400 doesn't have a lock up converter.
So can someone point me to some threads converting to a 454 TBI? Also to whom might be able to modify a prom? I'm not planning a real radical SBC.

Re: 1988 C1500 carb conversion
 

I would try a 454 computer to control the modified motor, or just the prom from one. I think certain injectors are selected also to keep things in range.

Re: 1988 C1500 carb conversion
 

Did you check the link in my last post? Seems to be "the man" on this topic. I have thoughts of installing the TBI and 4L80E out of my '95 into my '72 K2500 if and when I'm done with the '95. I plan to build a 383 for the '72

Re: 1988 C1500 carb conversion
 

The stock 454 TBI is around 670cfm where the 350 TBI is only around 500. The 454 unit will bolt to the stock 350/305 intake manifold but you have to open up the holes as the 454 unit has a 2" bore vs the 350 at about 1 3/4". Bump up the fuel pressure to 20-25psi. It will run fine on the stock 350 ECU but a custom chip will work much better. The TBI really is a simple system that works well.

Re: 1988 C1500 carb conversion
 

Yeah I did miss the link. Thanks for that. I will check it out. This TBI stuff is all new to me. I went from SBC to LS years ago and didn't look back.
Although I haven't bought anything yet I'm looking for more of a retro look engine wise with a good increase in power.

Re: 1988 C1500 carb conversion
 

I thought your user name came from being Larry Smith or something :lol:. I just found that site the other day. I'm going to bookmark it. I'm glad it will help. TBI is a mid-modern thing these days, I guess. People don't get excited about them because they never came on anything with impressive power. In that era TPI was the bomb. I'm thinking Vortec heads, Export Van TBI manifold, and that guy's TBI dealeo on a 383 for a long term motor in the future

Re: 1988 C1500 carb conversion
 

I'm not Larry Smith. I have been going back and forth to keep the SBC or go LS dressed like a SBC. It's hard to make a LS look like a SBC completely due to the steam cross over and water pump. Plus hiding the coils.

Re: 1988 C1500 carb conversion
 

Yeah. They look good at a glance. It will bug me to see Vortec heads on a SBC once I use them. It just doesn't look right without the signature paired exhaust ports, but 50hp is a lot of gain.

In the mid-90s I built a pro-street '69 Stepside big block sleeper using a 450 horse LS6 crate motor. I dressed it to look like the original 396 except for the custom taller dual snorkel air cleaner. The rear wheels where custom-built steelies I ran hubcaps on. I like what you plan for thise build

Re: 1988 C1500 carb conversion
 

There's adapters out there to run a BBC water pump on the LS's. Also numerous ways you can run custom plug wires and mount the coils remotely to simulate a distributor. I had a picture of a Riviera from a few years back that did a really good job of disguising itself. Run a 4150 flange LS intake and then a holley terminator x stealth throttle body set up and you're good to go.

https://www.lsclassic.com/coil-reloc...-plug-wire-set