Vortec carb swap?

[98k15]

I have a 98 k1500 with a vortec 350, I've been having problems with intake leaks, fuel injection system and the pcm, I know to carb swap it I need the intake for vortec heads, a carb, an hei distributor, pressure regulator or different fuel pump, what I'm needing to know is what cfm carb to run and I'm wanting to get rid of the pcm completely, I have an nv3500 so the pcm isn't needed for that but I do have an electronic shift transfer case, is the pcm needed to control it and can I use the factory hvac and gauges with the carb setup without having the pcm.

 

[kennythewelder]

Carb, nothing bigger than 650 CFM. Not sure about your transfer case.

 

[bluedevil]

This may or may not be helpful, but I built 97 rcsb carb vortec with an nv3500 (2wd though). The heater will work fine, as you will leave the red power wire on the pass through harness (pass side of the truck under the evap canister). Your t-case and trans wiring runs through there also. There are 2 more small connectors that plug in from that pass through, just inside the cab of the truck, next to the heater motor/ heater box, I just can't remember what they were for. I did not run A/C, so without the ecm, I don't think it will trigger the pump. Again, my memory is a little fuzzy, lol, but besides that you will leave;
-Starter signal wire (yellow or white),
-Pink coil wire to power the hei dizzy,
- Brown signal wire to the alternator,
- Grounds,
- You can just tie in keyed power to the reverse sensor on the nv3500, and tie the other wire into the reverse wire in the tail light harness,
-I left the under hood fuse box intact, but got rid of all the un-necessary wiring, deleted the abs motor, and its associated wiring, and any extra relays and fuses,
- I ran an aftermarket fuel pump, and different fuel tank setup, so my wiring there was simplified. I would go with a TBI pump if you wanted to run the stock tank, and wire it up to a safety switch,
-As for gauges, they get the info from the ecm. I ran a full autometer cluster. I can't help on the t-case, but you could always switch to a manual shift down the road.