tbi 454 thoughts...any experts?

[gonefishin]

I am going to resurrect my c1500 from the grave. I had a minor wreck in it about 6-8 years ago and then about 4 years ago I pulled the engine to put in my blazer. anyway I am in need of a truck to pull my boat etc.

I have had everything from a tbi v6, tbi 350, to a 375 hp carbed 350 in this truck. But with the only one that pulled decent was the carbed 350 and it wasn't that impressive either.

I am really wanting to put in a 454 tbi with a mild cam, headers, ebl computer system, and maybe a edelbrock intake. nothing radical just looking for about 300 hp and LOTS of torque. hopefully somewhat decent mileage too. I will be running a nv3500 and 3.08 gears. so my rpms should be low enough.

what kind of mileage can I possibly get 14-15?

also I know they went from mark IV to gen V in 1991 so is there any difference in the heads from the tbi trucks during that time? I have read bad things about the gen VI vortec heads for the big blocks along with the non adjustable valve train issues. do the gen V have the none adjustable valve train too?

so anyone have any thoughts other than LS or 8.1L?? anything I need to know as I have never messed with big blocks before.

I have found some lower mileage tbi motors in the 3-600 range that are supposed to run great. and I am on a budget so some of the upgrades will come in stages as funds allow after its on the road. sorry for such a long post.

 

[tRustyK5]

With the NV3500 I'd run 4.10's to make OD usable and less lugging which is hard on a weaker 5 speed. I'd say 10-12 is more likely...other than that it wouldn't take much cam to hit 300 hp and plenty of tq. Probably be able to retain the TBI and hit those numbers. IIRC they were 230 hp and 385 tq stock.

The TBI 454 I had I measured lift at the valve and it was quite low, like .380"

 

[gonefishin]

thanks for the info, I guess I can live with that mileage lol.

The ebl computer is just a replacement computer that allows the use of a wide band o2 so that it basically learns the fuel curves and makes for easier tuning. I will still use the stock throttle body system.

I also currently have the 3.08's in the rearend and I ran that with the getrag version of the nv3500 for years...

 

[82355]

Those tall gears are what made the other engines seem so weak.

Martin

 

[tRustyK5]

agreed...

 

[Greg Ducato]

My 88 Burb had a mild TBI 454 build, I used the Comp cams full roller set up, Eddy intake, bored TBI, adjustable regulator, Thorley tri-y headers etc. It had 4.56 gears and 35 inch tires. I got consistent 8-9mpg everywhere I went with the A/C running. The power was great and there seemed to be no hill in these parts that could pose a challenge and require the trans (700R4) to drop out of overdrive to climb. By comparison, the 1989 Burb I have now with 5.7 TBI, bone stock, 3.42's and 31's is getting just over 10mpg in the same type of driving, but not near the power. If I had it to do over, I think I would stroke a small block and this is the route I will most likely take on my current truck.

 

[80' 427]

Gears will make a great motor have no power and a weak engine seem snappy.

 

[79rustyk10]

What about a TBI 350 with a better rear gear? The torque from the 454 would be nice for sure though.

 

[gonefishin]

Ok so after a couple weeks of searching for a 454 I haven't been able to locate a decent one for a good price... I am going to keep looking, but today at the junkyard I found 2 6.0's that someone already butchered and left the hoods off. I also found a couple 5.3's that had the oil pans missing. So now I am considering going back on a regular basis and snag a 6.0 for it instead.

Think that would be a better swap?

 

[Greg Ducato]

I have a decent 454 you can get into cheap, pm me if interested

 

[454Sub]

A TBI 454 will produce more torque than just about any 6.0 they offer in the trucks. Period. Possibly the LQ9, but Im thinking the 454 has it bested by a few tq. Factor in power to weight, ehhh, the 6.0 wins then. But, the 100lb or so difference isnt noticeable in a truck and headers or a cheapie intake and a bit of work and the 454 is still ahead even considering the weight, not to mention much easier to install and get moving.

I went with a Gen VI motor, upgraded to adjustable roller rockers. Which was simple and reused factory pushrods, bought a dual plane carb intake for oval port heads, and bolted my TBI to it and called it a day. Now I have no emissions or any of that, but I have considerably more power than a TBI 454, and considerably more power than my brothers LQ9 6.0 as well.

 

[gonefishin]

I know I said no 8.1 but I thought that they were out of my price range. I found one running with all the accessories harness and computer for 600. But it has 200k on it. Is this thing worth it? I have read about several people having over 400k on theirs. What do yall think?

 

[paratrooper307]

I know I said no 8.1 but I thought that they were out of my price range. I found one running with all the accessories harness and computer for 600. But it has 200k on it. Is this thing worth it? I have read about several people having over 400k on theirs. What do yall think?

For 600 dollars, absolutely. You have the option of running it for a while and then rebuilding it when needed. Or you can buy it and spend some time and money freshening it up. Either way you come out ahead based on what they typically go for. Just check it out and make sure it's sound and doesn't have some hidden problem.

You will have to budget some money to drop it in, Larry on the forum has a really good write-up on what it takes to install an 8.1.

 

[snowdriver]

I know I said no 8.1 but I thought that they were out of my price range. I found one running with all the accessories harness and computer for 600. But it has 200k on it. Is this thing worth it? I have read about several people having over 400k on theirs. What do yall think?

jump on that