1993 TBI 454

[Jason Glover]

Hi guys, I‘ve got a 1993 GMC K3500 with a stock 7.4. It’s getting up there in miles (150K) just had the tranny rebuilt etc. my question is this. I’m planning on either having to replace or rebuild the motor in the next year. By rebuild I’ll have to have someone do it as I’m not that knowledgeable. Some options I’m considering and the questions pertaining to them are:
1. Considering buying a crate engine, likely a 454 H:O, my question is what else will need to be done besides the swap, how
Will the engine be controlled or will my current TBI/ECM work?
2. Trying to put a newer Vortec 454 in it. I haven’t been able to find a good article or thread on the swap, so I’m not sure if it’s feasible, what all would need to be swapped, PCM etc.
3. Building the current Gen 5 in it, and adding heads, cam, intake, etc but again after that many performance upgrades on a lackluster motor, how do I control it? Thanks in advance I appreciate the input
P.S. I briefly considered LS swapping for a 6.0 but I don’t want to go that route.
P.S.S my county in SE Texas does not have emissions testing!

 

[Schurkey]

150K miles does not seem like enough to require a rebuild. What problems are you having with it? I would be verifying fuel pressure 'n' volume, and all the usual "tune-up" stuff--cap, rotor, plugs, plug wires, air filter, cranking compression, throttle operation (do you get full throttle?) etc. along with checking for timing-chain wear. Run a 20-oz bottle of Techron in the gas tank to clean the injectors. Make sure all the rocker arms are moving about the same amount--no flat cam lobes. How old is the O2 sensor(s)? Is the initial timing correct? Does it advance like it's supposed to when you plug the timing connector back in?

The TBI system is moderately intolerant of modifications, at least without re-programming the PROM that controls operation. Reprogramming is -not- my area of expertise, and I'm getting out of the way of anyone else that wants to advise you on that.

A Vortec 7.4, or even putting Vortec 7.4 heads on your TBI short-bock would provide a small improvement in power. "I" would just put the TBI intake manifold on the Vortec long-block, install the TBI distributor, and connect everything as if it were a TBI engine.

Upgrading the exhaust is very worthwhile. The Vortec 7.4L muffler was exceptionally restrictive, the TBI muffler may be just as bad. Changing the muffler made more difference than installing headers, on my friend's '97 K2500.

 

[Brian Leemhuis]

I’m in the same boat with the high mileage big block. My issue is a weeping two piece rear main and the never ending quest for more power. I’m considering an aftermarket eBay motor or the Edelbrock performance top end and a short block prep.

 

[andy396]

I did a L19 to L29 swap. Follow the link in my signature. If I didn’t have a donor truck I would have just done vortec heads, upgraded the cam and exhaust. Getting the tune right was my biggest worry.

 

[454Keith]

Just picked up an '89 C-3500, ext cab, long bed, TBI 454/TH400/Dana 70, 4:10 gears, with 74,000 miles... Truck was bought specifically to haul a camper, which, incidentally, came with the truck! The camper is a heavy *******, ' 92 Lance Squire 8,000...

Guy I bought it from didn't do much more than change oil/transmission fluid regularly... Had a bad TPS, kept driving it, plugged the cat, and caused a bunch of sensor-related havoc... Radiator was pretty much plugged with stop-leak...

Replaced radiator with a nice tig-welded 4-row... Ditched the TBI stuff, went with an Edelbrock 750, MSD billet HEI, Quick Fuel regulator, new plugs, Taylor wires, cat-delete, and a welded Flowmaster knock-off... It's now almost a proper big-block Chevy... Next will be a good set of headers, dual exhaust... Am seriously thinking about Edelbrock heads, intake, cam, etc... We have hauled that big-ass camper three times so far, and she pulls great, considering... Just got a set of bags for it, and will probably do a sway bar out back... Camper will stay for now, but will eventually get a 19'-21' gooseneck or fifth wheel... Truck had a fifth wheel at on point, so should be an easy transition... It's just nice to drive a big-block again! The TH-400 has a kit in it, and is in great shape... It does need a LSD/locker at some point...

You must be registered for see images attach

 

[454Keith]

Just picked up an '89 C-3500, ext cab, long bed, TBI 454/TH400/Dana 70, 4:10 gears, with 74,000 miles... Truck was bought specifically to haul a camper, which, incidentally, came with the truck! The camper is a heavy *******, ' 92 Lance Squire 8,000...

Guy I bought it from didn't do much more than change oil/transmission fluid regularly... Had a bad TPS, kept driving it, plugged the cat, and caused a bunch of sensor-related havoc... Radiator was pretty much plugged with stop-leak...

Replaced radiator with a nice tig-welded 4-row... Ditched the TBI stuff, went with an Edelbrock 750, MSD billet HEI, Quick Fuel regulator, new plugs, Taylor wires, cat-delete, and a welded Flowmaster knock-off... It's now almost a proper big-block Chevy... Next will be a good set of headers, dual exhaust... Am seriously thinking about Edelbrock heads, intake, cam, etc... We have hauled that big-ass camper three times so far, and she pulls great, considering... Just got a set of bags for it, and will probably do a sway bar out back... Camper will stay for now, but will eventually get a 19'-21' gooseneck or fifth wheel... Truck had a fifth wheel at on point, so should be an easy transition... It's just nice to drive a big-block again! The TH-400 has a kit in it, and is in great shape... It does need a LSD/locker at some point...

You must be registered for see images attach

You must be registered for see images attach

 

[Schurkey]

Nice hot-air intake.

 

[Jason Glover]

You must be registered for see images attach

You must be registered for see images attach

Did you get anything from the wishlist don this year?