I got this 3.1, and its slow. Some im saving to throw in a 350 and a manual transmission. Would a 4bbl high performance carb do me better than tuned port injection? I hear that injection is better for throttle response but that theres more power in the long run with a carb. sooo?

 

Not an expert on TPI but i think they were originally designed for the 305....

So a 350 TPI would be a good motor and you can make some decent power......but no real HP with the stock TPI setup

 

I'd go with the 350. The 3.1 V6 cannot be back-engineered to a pre-smog performance engine like the 350. Even if a four barrel could be put on your 3.1, it wouldn't help. Buick had a Q-Jet on its 4.1 V6 and you could barely tell when the secondaries opened.

 

Anybody who says that TPI has better throttle response than a properly tuned carb, then they;ve never drove a properly tuned muscle machine. Carbs are definately more reactive, powereful and easier to troubleshoot, but the gas mileage sucks. If you go with tpi your going to have to get a 350 computer and injectors cause if its a 305 donor then the 350 won't run well. TPI is hard and expensive to make any real power, thats why I ripped mine out and went carb all the way.

 

To a point. TPI is designed to give better throttle responce on a "small" cube engine and on a small cube engine it does. On a larger engine you cant really tell.

 

The TPI was originally designed for the 305. It just so happened that the 350 got the TPI setup also. The TPI works great on a 305, or any other small cube engine, but on a 350; it just gets to a point where it restricts the engine. I would put the carb on the 350 over the TPI. The TPI has better driveability, throttle response and gas mileage, but for all out performance, the carb is a better choice.

 

Alright awesome - now the question is a 305 TPI or 350 4bbl?
I know theres alot more power to be found in the 350, but gas efficiency would be a f-in pocket strain.

 

Car in sig gets 18MPG city easy.

It all depends on what you have avalible and emmision requirements. If you have to get smog checks its probably easyer to wire in a tpi on either engine and pass. 305 as a rule gets better mileage and a cc system as a rule gets better mileage than a carb. It all depends on what you are willing to do. A guy over in the V6 board just put a TPI 305 in his six I would go over there and ask around. I cant remember his name, but the post is only about a month old so it should be easy to find.

 

Are you getting a Junkyard 350, or a crate 350? you might want to look into a LT1 or LS1 swap, though i have heard that they are $$ and time consuming.

 

There's nothing about TPI that can't be fixed so it will handle a 350, and handle it well. The issue there, though, is that it will run you some bucks. A co-worker has a ZZ4 TPI setup that runs 14.4's at our altitude (that'd be about 13.4's at sea level), gets 18-20 mpg, and passes our dyno emissions testing with a "fast pass" (emissions so low on the initial portion of the test that it doesn't have to go through the entire test).

What it took to get there - well, more for what he's done to the engine than what I've got in my entire modded and newly repainted car - and his still needs paint...