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454 tbi rebuild thoughts.

imiceman44

imiceman44

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So I have a 93 454 tbi that has 190k miles, is a running engine but has been sitting for years in my shed and I am thinking maybe freshened up or upgraded if there's anything worth the cost.
Roller cam upgrade?
Mpfi upgrade?
Thoughts?
It will be going in a crew cab for hard work.
In case I don't want to bother with the diesel I was planning on putting in it.
 
Good video on that engine here. I don't care for the peanut port heads but here's a decent video on how he built his and dyno graphs.

@Bent77 I don't think its a roller cam.
 
Somewhere in there, they started using rollers under tbi. L29 for sure
 
Bent77 said:
Somewhere in there, they started using rollers under tbi. L29 for sure
Click to expand...
I would love it if mine was a roller, but I doubt it.
The video that @Fastereddie posted is interesting.
I wonder if I raise the compression by milling the head or decking the block instead of changing pistons and I add a similar cam.
That is pretty much what I would like to have, more low end torque.
Not sure if the TBI will still run ok with that cam, or I have to go aftermarket like proflo
 
Well look first for sure, a friend of mine has 2x TBI era blocks that are in fact roller installed from the factory
Maybe some of them are flat tappet in a roller capable block, like they did the TBI era small blocks

I'd have to think the factory 7.4L ecms (7747 and 7060s) are tight parameter on the vacuum characteristic changes. SO adding some compression, opening the ports, no big deal.
Adding a bunch of cam, no bueno

But comp cams still lists ECM friendly cams for those
 
Bent77 said:
Well look first for sure, a friend of mine has 2x TBI era blocks that are in fact roller installed from the factory
Maybe some of them are flat tappet in a roller capable block, like they did the TBI era small blocks

I'd have to think the factory 7.4L ecms (7747 and 7060s) are tight parameter on the vacuum characteristic changes. SO adding some compression, opening the ports, no big deal.
Adding a bunch of cam, no bueno

But comp cams still lists ECM friendly cams for those
Click to expand...
Being a 93 I say chances are it might be roller cam ready.
That would be nice.
I am hoping next month to have some time to start exploring what I really have.
In the meantime, keep em coming
 
imiceman44 said:
So @mrk5
Is your 454 gen 4 or 5?
How do you like it with the proflo4?
Click to expand...
Mine is a Mark IV. I don't have the pro-flo on this engine tho. It has the Holley Sniper. I'm happy with how it runs.

I'm going to try a cam swap in the future. It's great for 90% of what I do but I'd like a little more power for towing our 4600# camper.

Hauling itself around it does great. I can pull all the mountain passes at speed. I'm super happy I did the engine swap. I wouldn't run a 4 door squarebody without a big block if there was anything I could do about it.
 
Granted, he put in domed pistons, but you can probably accomplish the same thing with gen 6 heads, which will bump the comp. ratio.
I mean, look at that torque curve. That's a mild build.
Just saw i put up the same video!
Been thinking on replacing the 6.2 with the 454
 
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We need to get some clarification. I was told Gen VI heads didn’t work on the earlier blocks.
 
hmmm
In one of his gen v vs gen vi videos, Holdener talked about swapping them.
(Later)
Did some reading, the general consensus is that gen 5 heads caused some coolant seepage issues when used on a mark 4 block due to coolant passage changes on the mk 5.
The mk 5 was considered a flop, so the gen 6 was born. It was considered by GM to be a bbc version of the sbc Vortec head.

I have experience with exactly 1 454 that I put together out of a 76 wagon.
Used the stock heads, comp cam 292 cam, 10.2 compression.
Sold it before I could run it due to job transfer (BRAC).
 
I believe you can get gaskets to run whatever combination you want with big block heads, but I haven't tried them all myself so their may be exceptions I am not aware of. But they do make gaskets to run the heads with certain blocks if needed. I think Gen V (91-95) is the one you have to worry about the correct gasket because I believe they fixed that issue when they designed the Gen VI.

If you study the gasket coolant holes against the block and heads before you bolt them together you can avoid the issue.

Most aftermarket head are designed to work on all the blocks, Mark IV, Gen V & VI. Not Gen VII 8100 which is the only stock symmetrical port and won't just bolt up as the head bolt pattern is different.
 
To answer the original question, yes you can wake that right up, depends on what you want to do to it.

Aftermarket EFI will allow anything to happen, and a cam and headers will really liven it up, after that, the heads are the bottle neck in both performance and the most cost to upgrade. They do make some aftermarket small chamber heads to bump compression up without changing pistons, but it would be cheaper to change pistons if you do the work yourself.

If the block doesn't have a mechanical fuel pump boss, its most likely the Gen V block. And it should have roller lifter provisions in both Gen V and Gen VI, but that doesn't mean all Gen V engines had roller lifters, roller lifters can be added to either, and is worth the cost if its in the budget.

A cam, intake, and headers can really wake it up. Along with the proper carb or EFI. I don't mess with the GM TBI, it's too much of a bottleneck, but it can be done within limitations.
 
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