1997 4.3 swap questions

[TheTitan97]

Hey guys brand new to this website, but have some questions on a swap I'm wanting to do. I have a 97 Chevy standard cab short bed with the 4.3 liter v6. Well I'm using it as my daily driver and it runs perfect but of course no real power of any kind. I have an engine out of an old blazer I built up its a small block Chevy 400 carbed. And the truck just sits and its rotting all to hell. Theres MAYBE 2k miles on the 400. And as much money as I have in it I don't wanna let it sit and rot. So I'm wanting to swap it with my 4.3. my questions are am I better off leaving it carbureted or should I put tbi on it. I'm wanting to put a decent sized cam in the 400 and I don't know much about tbi but I do know a large cam will make the computer go nuts. Keep in mind it will be my daily driver, occasionally going long distance but very very occasionally. I know my mileage will go to crap, I think in my big k5 I was averaging around 10mpg but I'm hoping with out it carrying around a heavy blazer it'll help a little, plus IL be using the 4l60e transmission that's in I have a buddy that knows how to make it work with a carbureted engine, so maybe that fourth gear will help too. I'm sure most people will say tbi would be all around better for what I'm doing but id like some other opinions on it, id like to make the truck a badass but at same time badass and daily driver don't mix to well haha. Who knows I'm prolly way off on stuff. Lemme know what ya guys think!

 

[skylark]

personal opinion here. Don't waste your time going carbureted. You'll have to regulate down the fuel pressure, your gauges wont work, the tranny issues can become nightmares, the frame mounts are different, the radiator may not be adequate, a built 400 should eat 4L60E's for breakfast and you still have a gas sucking pig.
I personally wouldn't even bother with a regular small block. If you want to do a swap that has reasonable power, gets decent mileage and works a lot better, look into a mild built 5.3 LS engine. Sell your 400 and the crusty pile of junk that is around it to fund your engine swap.

 

[TheTitan97]

I dint think about the transmission thing, come to think of it when I built the 400 and put it in my blazer it destroyed the 400 turbo transmission I had also put in it brand new, I had to go with some performance turbo 400 from certified transmission I think the street dominator its called.. so your prolly right it'll eat the 4l60e, there not that great of a transmission anyways. But I do have two other options. 1. I have a chance to buy a tbi 350 I could swap into it, or 2. I could rebuild the 4.3 that's it in, I think they sell decent cams for them, I could bore it .30 and port the heads, ect ect. give it a slight power boost I suppose. Iv read threads of people rebuilding the 4.3's but the results are all over the place so I'm a little hesitant on that.

 

[skylark]

Option 1 isn't that great of an idea because the tbi system is very basic (I like it though) it won't run your gauges, you still have to swap frame mounts, regulate down the fuel pressure from 60 to 13, and honestly the tbi 350 really isn't impressive (190-210hp/300tq). I have a 93 with a 4.3 and it will be getting a 5.3 with at least a mild cam and a tune 285hp/325tq stock. I don't have the gauge issues or 4L60E that you do so my swap will be easier but I have a tbi system so I will have to do some work on the fuel side.
Option 2 will never make you happy unless you want to go forced induction and just simply do something different. I have been down the built V6 road and I can tell you that once again, an LS is in the future. If you were going to swap anything else and you want a small block then honestly I would just swap in a vortec 350 with a mild cam and a mild (2500-2800rpm) stall converter with a set of 3.73 or 4.10 gears.

 

[ccreddell]

Having been there, and done that, I have to agree with Skylark. And seeing as he has my old truck with the V6 in it, it's probably why we agree. The thing to remember is that fuel injection isn't just about mileage and emissions-it's about efficiency. Which is why NASCAR went to FI. Efficiency doesn't only deliver fuel mileage, it unlocks horsepower an torque. So, whatever engine you decide to go with, stick with FI. Now, that being said, I'm still not that impressed with the LS motors in a truck. They're too high Erving, and just don't have the grunt to make a great truck engine. The heads actually flow too well and develop most of their good power up in a range that can be uncomfortable in a heavy truck. Don't get me wrong, they are a fantastic engine family, and if I had the chance (and the money to modify them for truck duty), I would snatch one up in a heart beat. But for good all around every day use, I'd stick with either a Gen 1 or 2 smallblock. A regular 350 with a roller cam and a decent FI system will be efficient and powerful. A Gen 2 LT1 ups the anti a bit more because of its aluminum heads and reverse cooling. It allows you to run 10.5:1 compression on pump gas which equals more power and mileage-if you keep your foot out of it. Running a newer computer with all that helps a little too.

 

[skylark]

Having been there, and done that, I have to agree with Skylark. And seeing as he has my old truck with the V6 in it, it's probably why we agree. The thing to remember is that fuel injection isn't just about mileage and emissions-it's about efficiency. Which is why NASCAR went to FI. Efficiency doesn't only deliver fuel mileage, it unlocks horsepower an torque. So, whatever engine you decide to go with, stick with FI. Now, that being said, I'm still not that impressed with the LS motors in a truck. They're too high Erving, and just don't have the grunt to make a great truck engine. The heads actually flow too well and develop most of their good power up in a range that can be uncomfortable in a heavy truck. Don't get me wrong, they are a fantastic engine family, and if I had the chance (and the money to modify them for truck duty), I would snatch one up in a heart beat. But for good all around every day use, I'd stick with either a Gen 1 or 2 smallblock. A regular 350 with a roller cam and a decent FI system will be efficient and powerful. A Gen 2 LT1 ups the anti a bit more because of its aluminum heads and reverse cooling. It allows you to run 10.5:1 compression on pump gas which equals more power and mileage-if you keep your foot out of it. Running a newer computer with all that helps a little too.

I would agree that the LS doesn't make good power down low like the GEN I or II. In the case of the 93 I would have left it as a 4.3 but I kept hearing comments like, LS swaps aren't that expensive, LS is easy, LS can be done for under 1K. You know what? They are right for once. I don't mind the lack of low end torque because like I told you when I bought the 93, I couldn't drop a stock small block in there and I don't feel like picking up NV3500 pieces off of the ground.

 

[TheTitan97]

I shoulda worded my option 1 a little differently, its (I believe) a vortec 5.7 I just say tbi 350 I thought it was the same thing but I see what the difference is. The engines coming out of a 95 suburban. So everything should hook up to the gauges in my 97 truck correct? If that's the case I may go that way, the truck already has 3.73 gearing so id Polly rebuild the 5.7 with mild cam like skylark had mentioned. honestly being a daily driver id be happy with horsepower in the 250 to 285 range I was wanting anywhere from 300 to 350 horsepower which I'm sure was possible with my 400, but its not really practical in an everyday driver. And on option 2. Seems like id have to put gobs of money into a huge 4.3 build just to get it to where a mildly built vortec5.7 would be from the things iv read.

 

[ccreddell]

Nope. 95 is still a non-roller TBI motor. Yeah, the 4.3 is a great motor, but its not really worth building. My fairly stock build LT1 is projected to run around 375HP and 400ft.lbs. with an LT4 hot cam and a TPI intake. Will idle slightly better than a stocker and (hopefully) get into the 20s MPG wise. We'll see....

 

[ccreddell]

Oh, and Charlie, I wasnt putting you down at all. It was what I had in mind for that truck too.

 

[skylark]

I shoulda worded my option 1 a little differently, its (I believe) a vortec 5.7 I just say tbi 350 I thought it was the same thing but I see what the difference is. The engines coming out of a 95 suburban. So everything should hook up to the gauges in my 97 truck correct? If that's the case I may go that way, the truck already has 3.73 gearing so id Polly rebuild the 5.7 with mild cam like skylark had mentioned. honestly being a daily driver id be happy with horsepower in the 250 to 285 range I was wanting anywhere from 300 to 350 horsepower which I'm sure was possible with my 400, but its not really practical in an everyday driver. And on option 2. Seems like id have to put gobs of money into a huge 4.3 build just to get it to where a mildly built vortec5.7 would be from the things iv read.

As ccreddell said, is 95 is just a tbi engine.The vortec will have 8 intake manifold bolts pointed straight down at the ground. A TBI will have 12 intake bolts pointed directly at the heads. The vortec series is 96-00 and into 02 in vans. I agree completely on your assessment of option 2.