89 3500 / 7.4 454 with TH400 Carb Swap

[unstable01]

I was on another forum and I was pointed to this forum because of a tech article on ridding myself of the TBI system and replacing it with a carb.

Despite working on computers to earn a living, I don't like having a computer run the motor in my vehicle.

From what little I have been able to research I will obviously need a new distributor (HEI), an intake manifold and a carb.

I have the TH400 transmission so I don't have to worry about any computer controls there. I'm just concerned about what the dash is going to do once I get rid of the TBI and the computer controlled dizzy.

Any additional insight is appreciated. I apologize if this has been addressed before...I couldn't find any articles here.

[Bad Bowtie 91]

Alright, keep your oil pressure sending unit, water temp sensor, and alternator wiring and the gauges will work like they did from the factory, mine still do. Keep the pink and white wires from your coil to power the HEI dizzy. Pink for power, white for he tach and your set.

No other sensors or wiring is need, EGR, knock sensor, 02 sensors can be cut off and heat shrinked.

Might as well go ahead and pull the service engine soon light as it will always be on afterwards.

You'll need a fuel pressure regulator with a bypass return line back to the pump, if you plan on using the in-tank pump. Most run either a Holley 12-803BP regulator ($70. from Summit) Or a Mallory 4309 ($100 at Summit)

[unstable01]

thanks for the response! I guess the only other question that I have at the moment is...I read something about IF you have a roller cam that you'll need a bronze distributor drive gear or something along those lines...does this sound familiar?

I'm not sure if the cam is roller or not. Is there a way of ID'ing this off of casting numbers or VIN or something?

I'm looking at having a donor 454 rebuilt in the very near future, so it shouldn't be too big of a deal but I'd like to keep the tired old 454 that is currently in the truck running until I'm able to make the swap...in fact, I might just hold off on the carb swap until I do the motor, it will be easier to get everything in order.

[Bad Bowtie 91]

yes, if you do infact have a roller cam block you will need a bronze gear.

The easiest way to tell if its's roller or not si, pull the valve cover and look at the rockers.