Blew the 400 up

[PlayingWithTBI]

Plus I like the idea of 4 jets.

That's up to you but, I don't have to tune my TBI every time the weather or elevation changes

As an example, Fueling (VE) and Spark Advance tables. I don't need any tools either, just plug in my laptop and tune. If I need a little more pump shot out of the hole, I just add a little to my AE table, plus more goodies. With my WBO2 sensor, I can dial in all ranges of the spectrum - just saying

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[Schurkey]

The Q-Jet pictured has the idle air bypass. Nice. May or may not be useful, but it's worth trying. Generally more-helpful on larger-displacement "Big Block" engines. The worst that can happen is that you'd tap the bypass holes in the throttle body, and plug 'em with set-screws. Tap from the top side, DON'T tap all the way through the casting so that there's no possible way for the screws to come out the bottom--into the intake manifold. And God bless Loctite thread lockers.

I love Q-Jets, but there's no way I'd remove a TBI to install one on a small-block pickup truck. (That goes quadruple for one with Swirl-Port heads.)

 

[L31MaxExpress]

The Q-Jet pictured has the idle air bypass. Nice. May or may not be useful, but it's worth trying. Generally more-helpful on larger-displacement "Big Block" engines.

I love Q-Jets, but there's no way I'd remove a TBI to install one on a small-block pickup truck. (That goes quadruple for one with Swirl-Port heads.)

I put a TBI engine together that had a 214/224 cam into a former 267 powered square body. Used the later aluminum intake of an 87 or 88 LG4 that had the revised bolt angle. Re-used the Q-Jet. With the swirl ports the fuel economy and torque was awesome.

 

[L31MaxExpress]

I pulled the computer crap q-jet off the 88 Fleetwood that I had 307 to 403 swapped. The 403 had 70 or 71 model 350 heads and matching GM aluminum intake with a mild mondello olds cam. Ran it for a year with the CCC Q-Jet, then installed GM TBI. It ran better with the stock 350 ECM and 454 TBI on a factory TBI to Q-Jet spacer than it ever ran with a carb. Once I did a little tuning and put an Olds advance curve into the TBI computer it ran like GM had fuel injected the car. Started with a twist of the key on the coldest morning, fast idled, drop it into gear and it would drive away smoothly. Out on the road it would get 26-28 mpg and always had plenty of get up and go. No more stumble from a carb trying to meter fuel at the stupid low rpm that the 200-4R and 2.53 gears resulted in. I actually miss that car because it did everything well. I later swapped a 4L60E into it using a Caprice LT1 dual exhaust crossmember. Used a 350 diesel truck exhaust cap and put a used factory LT1 caprice dual exhaust on it down to the factory cats. Dual exhaust let the 403 breathe and it sounded great. The 4L60E let me adjust the a
shift points with ease at both part throttle and WOT Which really brought that Olds up a notch. I replaced the accessory brackets on it to use an A6 compressor. A6 was quieter and more durable than the R4 and the ac cooled phenominally well.

 

[Deadman walking]

That's up to you but, I don't have to tune my TBI every time the weather or elevation changes

As an example, Fueling (VE) and Spark Advance tables. I don't need any tools either, just plug in my laptop and tune. If I need a little more pump shot out of the hole, I just add a little to my AE table, plus more goodies. With my WBO2 sensor, I can dial in all ranges of the spectrum - just saying

You must be registered for see images attach

I know what you mean but I could pass on that honestly. All I need is a screw driver vaccum gauge and a wrench and I'm good to go. Not really worried about elevation it's flat where maybe some hills here and there but whats a couple of hundred feet. If a carb is good and rebuilt and tuned proper I'll never have to spray starting fluid in it in the cold.

 

[Deadman walking]

The Q-Jet pictured has the idle air bypass. Nice. May or may not be useful, but it's worth trying. Generally more-helpful on larger-displacement "Big Block" engines. The worst that can happen is that you'd tap the bypass holes in the throttle body, and plug 'em with set-screws. Tap from the top side, DON'T tap all the way through the casting so that there's no possible way for the screws to come out the bottom--into the intake manifold. And God bless Loctite thread lockers.

I love Q-Jets, but there's no way I'd remove a TBI to install one on a small-block pickup truck. (That goes quadruple for one with Swirl-Port heads.)

True for the swirl port heads. But I'm gonna run it on the vortec block (it would run better with those heads though) after I get the carb rebuilt. Like I said I'm looking for a race truck since I've got lower miles better compression and have the provisions for a roller cam now. I'm not looking to do rolling burn outs at 40 miles an hour just a good hauling truck with a lot more torque. The MC 1988 RV cam was damn good with the TBI heads though I gotta amit that.

 

[letitsnow]

I know what you mean but I could pass on that honestly. All I need is a screw driver vaccum gauge and a wrench and I'm good to go. Not really worried about elevation it's flat where maybe some hills here and there but whats a couple of hundred feet. If a carb is good and rebuilt and tuned proper I'll never have to spray starting fluid in it in the cold.

I am curious to hear how your carb works out.

When I first bought my truck I too wanted to carb swap. I ended up sticking with the vortec efi and bought new injectors for about what a new carb would have cost. I did have one (no start) failure while pulling a camper across Texas - if it had been carb/hei swapped, I could have fixed it quickly myself. Part of me wonders what a carb would have been like.

Most here will tell you to stick with the efi. I have noticed though - most of the people that swear efi is better and talk about how easy it is to tune, they are always changing it. It's like they never quite get there. Sounds about the same as a carb to me haha.

 

[L31MaxExpress]

I am curious to hear how your carb works out.

When I first bought my truck I too wanted to carb swap. I ended up sticking with the vortec efi and bought new injectors for about what a new carb would have cost. I did have one (no start) failure while pulling a camper across Texas - if it had been carb/hei swapped, I could have fixed it quickly myself. Part of me wonders what a carb would have been like.

Most here will tell you to stick with the efi. I have noticed though - most of the people that swear efi is better and talk about how easy it is to tune, they are always changing it. It's like they never quite get there. Sounds about the same as a carb to me haha.

Only making changes here because I want even more power and have the parts hanging around to do it. Once I get the heads back on mine, the marine intake on it and get it dialed back in, mine is staying the way it is for some time.

 

[letitsnow]

Once I get the heads back on mine, the marine intake on it and get it dialed back in, mine is staying the way it is for some time.

Good story.

 

[RichLo]

Carbs get a bad rap here and I usually stay out of those debates because it really depends on the end user. EFI usually goes to the guys that want to fine tune every detail of the engine and carbs go to the guys who want to bolt on something reliable that will get the job done for cheap. Nothing wrong with either approach.

Carbs are dead simple and EFI are endlessly tunable... pick your poison.

This is all when considering a modified setup, if the engine is factory stock then just stick with the factory EFI.