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sierrablue 07-14-2022 10:34 PM

Buick 350 Injection
OK, I'm happy with the Qjet for driving around here, it's tuned right so I'm getting decent mileage (you know, for a brick with no overdrive or FI:p ). Trouble is I want to be able to cope with altitude, and it's always nice to have something just fire right up every single time, after letting it prime of course. And it'll help with colder weather, too, but anyway you guys already know the advantages of FI.

So on the B350, as I have the 4-barrel, I see two options. There's Holley Sniper for either the 2- or the 4-barrel manifold, which is the cheapest option that actually fits. I do not want to run an open adapter; if the barrels all line up and the bolt pattern's wrong, an adapter is ok, but I don't want an open adapter.

There's also the intake multiport injection from T/A Performance; but since that's 4k, it's out the window. Does anybody know of any other bolt-on TBI?

sierrablue 07-15-2022 11:12 AM

Just found this page--

Wouldn't mind more info on the 454 TBI though...

Herk 07-15-2022 11:17 AM

My plan is to just transplant a Rochester TBI off a 88-92 GM 5.7. Pretty straight forward. Info here

Have all the parts, but project is on hold until I can get some major sheetmetal damage fixed and get truck back on road

Achilles 07-15-2022 06:06 PM


Originally Posted by Herk
My plan is to just transplant a Rochester TBI off a 88-92 GM 5.7. Pretty straight forward. Info here

Have all the parts, but project is on hold until I can get some major sheetmetal damage fixed and get truck back on road

Are you going to tune it yourself? I have the parts for this, but have been considering the Holley Sniper as of late for ease of setup.

sierrablue 07-18-2022 01:10 PM

I'm curious about this too, as I know the GM TBI will be cheaper to do, but it's also more of a pain to tune. I'm sure somebody makes a program so you can use a modern computer for tuning it, right? The computer we used on the '88 TBI finally gave up the ghost and I'm not sure what to use instead. What're you using as a chip to start with? And I'm guessing you plan to tune it after that?

Is your plan still to use the 454 adapter to the 4-barrel manifold? I know the 2- and 4- barrels are both dual plane for these unless you get the Stage 3 intake from T/A, but the TBI can still theoretically take advantage of the dual-plane setup. And I know the 4-barrel manifold on the Buicks is just a much better design than the 2; the 2 is a weird shape and the Quadrajet isn't the only reason the 4-barrel makes so much more power/gets better mileage...

Thanks for the info Herk.

tgreese 10-08-2022 03:08 PM

I think the main appeal of the Rochester TBI is parts and service. It's all GM/Chevrolet, and any issues away from home can be fixed by most any mechanic, or by you with parts-store parts. The Holley system appeals for its easy tuning and one-source purchase.

I guess if you put a Chevy 350 TBI on a Buick 350 is will run and drive, if everything is connected right. I would expect to tune it after I was on the road.

There are sellers out there that will make a custom Rochester TBI for you, like Bill Hamilton. He sends you a bolt-on system with his best guess at the tuning. You collect log files and send chips back and forth until it's optimized.

Mopar_guy 10-09-2022 12:59 PM


Originally Posted by tgreese
I think the main appeal of the Rochester TBI is parts and service. It's all GM/Chevrolet, and any issues away from home can be fixed by most any mechanic, or by you with parts-store parts. The Holley system appeals for its easy tuning and one-source purchase.

If I may add some to this because I've dealt with the aftermarket TBI's for quite a few years now and if you expect to bolt on any of the aftermarket TBI's and just think you'll drive it, you'll be in the minority. The Sniper system uses some proprietary parts like injectors that can be hard to come by if it takes a dump in the middle of nowhere. It might be a bit of a pita upfront with tuning on the Rochester TBI but as he points out, parts are available almost anywhere where there's a big box auto parts store. I try to avoid as much aftermarket stuff as much as possible because of the amount of driving I do in my Hemi swapped Javelin. My Cherokee is going to be built along the same lines. Most of the aftermarket stuff is low quality with no support. The good stuff they do sell is expensive and usually works. Take into consideration getting support. Buying from a good dealer and paying more for good support is well worth it versus saving a couple of bucks upfront.

If your doing a FI swap based on your budget alone, stick with a carburetor if that's what you know because you're not going to be happy. It's not cheap upfront and takes time and effort to get it right but the payback can be good. Don't expect much mileage gain but driveabilty will be superior especially with today's gas. Fact - Overdrive will get you way more mileage than FI even with a well tuned carb.

Be prepared to learn about FI because you're going to need the knowledge. If you're not willing to do that, stick with a carburetor. Just saying because I've seen numerous guys buy an FI system just to pull it off 6 months to a year later and sell it at a big loss for a number of reasons.

Oh and the only place to to put the fuel pump for any FI system is in the tank. Anything else will fail and cause you more problems. It's a pay me now or pay me later deal. Trust me on that. ;)

sierrablue 10-10-2022 08:39 PM

On the FI on the '88, the pump that wasn't in the tank always worked; the problem was it was SOOOOOOOO incredibly annoying to listen to. For the longest time they didn't make in tank pumps for the stock tanks for these, so it was a pain (my uncle did that TBI swap in the early '00s--this was when everyone hated the GM TBI vs. a carb).

If I had to guess I'm going to stick with the carb, until I go EV. Really the "right" way to go on the Buick 350 is to get this kit from T/A Performance, if you have the money...

Like I said in the "Qjet at altitude" thread (, if I go to FI, I want something that actually follows the spread bore pattern--I don't care if the bolts line up, but it's the bore that I need. Having an open adapter in the middle; that just bothers me. But if you got the T/A aluminum intake, it has both the spread- and square-bore patterns usable, though you'll still have to adapt the TBI bolt pattern, if that bothers you.

rang-a-stang 10-12-2022 04:47 PM

I built/tuned my own EFI based on a 1995 GM 454 TBI system for my 401. Here is my experience/advice. Most of it is based on comparisons to the Howell kit which is pretty much a rebranded/repackaged GM TBI kit.

1) It works, you can do it. My EFI did control my fueling and timing. It also controlled my electric fan. My truck ran awesome when I was done with it. It always started (hot, cold didn't care), there were no flat spots in performance. You could just reach in the window, crank the key and it would start; no choke, no revving it to keep it going when it was cold, just start it like you would a new truck. Even if it sat for a month, turn the key and " RR RR broom". I could use the knock sensor to determine the perfect timing for almost all situations. It was a really good system.
2) I had an ABSURD amount of man hours in the system doing research and trial/error. I am not joking when I say HUNDREDS of hours. Which Idle air control valve? where to put the knock sensor? which knock sensor? how to "burn chips" to tune it? How to interface with the EFI? which computer to use? what is a BIN, XDL, a mask, a data log? No joke, HUNDREDS of hours....
3) YOU WILL NOT SAVE MONEY BUILDING IT YOURSELF the first time. You think you will because generally the big ticket items are cheap BUT you will nickel and dime yourself to about the cost of a Howell system building your own and you end up with a system that is half new and less reliable than if you had just bought a new Howell in the first place. I replaced a ton of old cracked connectors (keep in mind the newest TBI you can use, 1995, is now almost 30 years old and the plastic connecotrs and wires are dry and cracking). Also, the quality of the parts you buy when building your own system make it really unreliable. What I mean is you think it is way cheaper becuase you can get a $20 Temp Sensor from Rock Auto or McParts, but that sensor will only last a few months or a couple years if you are lucky. The good Temp sensor is $80 so you spend $20 on a crappy one, then $50 for a tow home becuase it failed, then you spend the same $80 for the quality one anyway. The Howell kit is a much better value in the long run becuase they already figured out what parts to buy.
4) Tuning fuel, timing, and other stuff is really awesome AND really stressful. It took me a couple months of tuning and learning before I ever really figured it out. I thought I was making it better but it was getting worse and worse. Once I figured out what I was doing, I got better at it but in the back of my mind, I always wondered if I was leaving performance/efficiency on the table becuase I was such a NEWB. It feels really awesome when you drive it and it runs like crap, you take a log, you analyze the log, see the problem, fix it, burn a new chip, and take it for a drive and make it better BUT it always gets super frustrating when you can't figure it out and you can't take it to a pro becuase you have a bastard system and no tech is going to touch it.
5) I think the questions you asking are pertinent and make it worth swapping. You will get some MPG increase. You will get many drivability improvements but none of them are drastic (except no choke and quick warm ups). You are not going to get a 20% increase in MPG vs. a properly tuned carb/distributor, you might get 10-15%. Also, if you have engine issues before EFI, they are not going to go away with EFI. So a tired engine with a carb is going to be a tired engine with EFI, except you will be banging your head against a wall trying to learn how to tune an EFI when the real problem is a vacuum leak, or old rings, or a cracked valve seat.

So, in summary:
A) Would I do my own EFI again? Yep, becuase I learned enough from my first attempt that it would be pretty easy to replicate since I learned so many hard (and sometime expensive) lessons.
B) Would I recommend a DIY system to someone else? NOOOOO!!!!! it is not worth the time AT ALL AND you are not going save any money. GET. A. KIT.
C) What would I recommend? Either Howell or Sniper. The advantage of Howell is you can add to it pretty easily and for those in Commiefornia, it has a CARB number. Much of the info on binderplanet, gearhead-efi, DIYEFI, and 3rdgen appies to it. The advantage of Sniper is cost and simplicity. Bolt it on, and it works. There are dizzys that you can get to add stuff but if you want to just pull the carb, and stick EFI on top, it's pretty hard to beat Sniper.

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