Im getting a "new" engine pretty soon, right now i have 2 choices. a 350 TPI , and a 350 carb, i can get more info later, but im thinking about swiching to carb because i will be doing a lot of upgrades, and it seems like losing the computer will simplify things.
any ideas on what i should do? (305 tbi now)

 

daily driver TPI is nice, weekend fun car only that will have a more radical cam then carbs make more power, but will cost fuel economy.

 

I agree, for a daily driver the TPI would be the better choice, but the way it sounds this is a fun car and not needed for everyday driving, in that case I'd definitely go with the carb setup. And if you want to drive it alot then I'd go with a economical carb like a non cc q-jet, which can make great power and yet still provide fairly decent mileage. I had a eddy 600 and actually removed it to put on a balanced and rejetted q-jet, and not only does it get better mileage but it actually makes the engine run better and with more power. I love my non cc q-jet. When taken care of and tuned properly they are nearly impossible to beat. If your lookin for max power with no worry about mileage then look at carbs like Holley, or BG. I like the Demon carbs too, cause the venturi's are changable. The BG's are great carbs if you talk to some and junk if you talk to others, seems nobody can make up their mind.

 

I vote go for carb unless gas mileage is a real concern. I wouldnt worry about driving a carbed car every day though. My T/A is my dd and its carbed. Ive never had any issues. Even in the dead of winter(can get pretty damn cold here in KS).

 

Thanks for the feedback. Alot of good points have been made. Probably going to go carb. but still not sure.

 

I'm more in the camp of "run what you've got". With rare sweetheart deal exceptions, it's not cost effective to switch from one system to another. If you're purpose-building (such as a car for the track), then that's a different story, too.

If you can get a complete 350 TPI engine and system for a decent price, swapping that in place of a 305 TBI isn't too difficult. If you have to piece together the TPI system, then you're better off sticking with TBI and upgrading it. If you're getting a 350 with a complete TPI system, it makes more sense to me to swap that system in than it does to convert the engine to carb.

You were pretty sparing with details, such as if you're getting a 350 and are trying to figure out whether to put a TPI or carb on it; or if you are looking at two different engines, one with TPI and the other with carb; how complete each is; what year model each is; and what your immediate and long-term goals are with the car.

Personally, I don't find computerless systems much less complicated than those with computers. It's more a matter of understanding what each does and how it does it.

 

true, my details were lacking, The tpi is no longer avalible to me, so im going to carb. The engine is out of a chevy van. im guessing late 80s early 90s. It has a quadrajet carb. Plan on getting higher flowing intake manifold and edelbrock carb, headers ect.
The cost of the 350 is $200 and it is a strong runner(not to high of miles).
Im really getting it out of necessity, the 305 i have in my car has 223,xxx miles on it. I figure the block should be a good platform to upgrade as time goes on

 

Truck engines didn't get the best pieces when it comes to passenger car performance. Most likely, it's got poor flowing torque heads - fine for what the factory does with it, not so good for trying to get more out of it.

I have no love lost for Edelbrock carbs. If you don't have a carb and want something that runs and gets you from point A to point B for the least amount of money, then they're fine. But, to spend money on one when you've got a functioning q-jet makes no sense - you're trading Carb Type A-A for Carb Type A-B; there simply is no advantage to an Edelbrock over a q-jet, there are disadvantages such as reduced fuel economy and power potential, so why spend money on something that will hurt you and won't help you? Seriously, stop yourself before you make an expensive mistake.

If the q-jet is computer controlled, then never mind - getting it to run in a TBI car is more trouble than it's worth. I still wouldn't go with an Edelbrock, though. A very good case could be made for sticking with TBI.

The van 350 block is a decent base for future expansion. It probably has 4-bolt mains (although that doesn't mean a lot), if '86 or '87 it will have one-piece rear main seal (better than 2-piece, IMHO). If '87 it will be a roller lifter cam casting, but probably isn't machined for the roller pieces. If '88-later, it would have been TBI.

Kind of hard to go wrong for $200, as long as there aren't any cracks in the block.

 

Thanks for the carb info. Ill keep that one in. also it isnt computer controlled

 

U.S. light trucks/vans should have gotten computer controls by 1985, certainly 1986 model year. The engine may be older than you think (or at least the van is), or somebody has done some modifications from factory.

Not a big deal, but could affect some of the details of the swap.

 

I agree 100% that edelbrock carbs are a waste of money, I had one and actually got rid of it and now use a q-jet with much better results. Gotta love the small primaries for decent mileage and massive secondaries for power. I think the q-jet was an excellent design and I would take it over many of the aftermarket carbs. Just gotta get one thats not computer controlled.

 

Also take into account your emission laws in your state. A carb motor will put out more emissions and be harder to pass at the station. Granted, you can lean it out a considerable amount, and this may or may not work for you.

 

No i was wrong, it is computer controlled. so im not sure on what to do about a carb. Can i make it not computer controlled? or i guess i have to find one thats not computer controlled, (dang this is a lot more complicated than i thought it would be LOL)
as for the emissions, not something im worried about, no cat.
BTW- the edelbroc that i was looking at was a 600cfm non-emission electric choke. if i cant get a quadrajet

 

OR... can i switch the 350 carb into TBI ( off the 305). Because then i wouldnt have to worry about my fuel pressure, nor change/ remove my computer. If i sound like a complete idiot for saying this its because i dont really know a lot bout this stuff. if i can do this it would save me some money.

 

Actually, I believe I already recommended that (keeping what you've got).

The TBI forum has a lot of information about getting LO3 TBI to work on a 350.

 

I've always heard the only big difference between 305 and 350 tbi is the injectors are bigger with the 350's, and even tho the computer programming is a bit different, the 350 can run fine with the 305 computer as long as its basically stock.

I have used 305 tbi on a 350 before and never had a problem, and that was before I even knew there was a difference.

 

Duh.. sorry. I think that might be a decent idea for now, but would i make more power with the carb or my stock tbi unit, Im guessing the carb because my tbi is meant for a smaller displacement engine.( maybe, thats just my uneducated guess). If i could put a tpi unit on there that would be cool, but my fuel pressure isnt high enough( I think tbi has 9-12psi maybe, where as TPI has somewhere like 40+psi) plus i think i might have to change my comp.
Its funny how something that starts so simple turns into a dang novel lol.

 

Carb will probably make slightly more power. Properly tuned, TBI will offer better fuel economy and driveability for the power. If you stick with TBI, the first thing you should do is get a 350 throttle body. Plentiful in junkyards. The second thing is to reprogram the PROM.

Switching to TPI would require changing the computer and all of the harnessing from the computer to the engine. It's best done getting all the parts from a complete TPI car. The in-tank electric fuel pump most likely will also need to be changed. It's the regulator that determines pressure, but the TBI pump from the factory isn't adequate to feed TPI (however, a TPI pump works fine for TBI).

TBI is the red-headed step child of the performance world. Not because it's a bad thing, but because the factory never optimized it on performance applications (we won't count crossfire), and the aftermarket didn't pick up the ball. However, Holley and others have stand-alone EFI systems that are basically 4-bbl TBI, so the concept itself isn't the issue.

 

Looks like carb is my best bet. Thanks for all the input! Learned a ton just from this.