4.3liter to 5.7 liter swap questions

[Shweezle]

I am in the middle of a 4.3 to 5.7 swap. My truck is a 1993 k1500 work truck so no accessories of any kind and a manual transmission. At just shy of 200,000 miles the crank shaft broke so I decided it was time to put a 350 in as well as a/c and power windows, locks ETC. I bought a 1994 k1500 Silverado with everything I needed but it is an automatic transmission. So I need to use the wiring harnesses out of the donor truck but I am running into concerns about auto vs manual transmission differences. The ECMs between the two trucks are different. Has anyone done this and if so what do I need to do to make the conversion. I don't know if it is the year or the transmission that makes the difference in the ecm. I need to eliminate all automatic transmission wiring and programming then I am wondering about the crank fuse the goes to the ecm for start up. I'm hoping someone can share their knowledge so I know my options.

Thank you

 

[Scooterwrench]

There are some differences in 88-93 and 94-95 ECM's Use your wiring harness. The 262 and 350 share the same throttle body with the 350 having larger injectors. Use your 262 TB and put the 350 injectors in it. Use the 262 EST module. Use the 350 knock sensor(leave it in). Use the 350 MAP and ECT sensors,they're the same but you may need to use the 262 mounts for the MAP. You may need to buy a 350 dist. and a 93 350 manual ECM. I think the clutch switch runs through the crank fuse.

 

[Shweezle]

Part of my problem is adding ac, I needed the interior harness for the controls. Can I swap The ecm connector wire for wire and have it work?

 

[Schurkey]

Fix up the '94, sell the '93?

 

[Shweezle]

Fix up the '94, sell the '93?

The 94 is junk, not fixable. The 93 was my son's truck that he left me when he passed away so it's pretty important to me

 

[Shweezle]

There are some differences in 88-93 and 94-95 ECM's Use your wiring harness. The 262 and 350 share the same throttle body with the 350 having larger injectors. Use your 262 TB and put the 350 injectors in it. Use the 262 EST module. Use the 350 knock sensor(leave it in). Use the 350 MAP and ECT sensors,they're the same but you may need to use the 262 mounts for the MAP. You may need to buy a 350 dist. and a 93 350 manual ECM. I think the clutch switch runs through the crank fuse.

Thanks for the info, it helps. I think I have a plan now.

 

[Scooterwrench]

To get A/C you will have to change the airbox,install the control panel and the wiring. Keep the manual windows and door locks they will still be working long after all those electric parts fail. When you buy the 93 ECM get one for manual tranny and A/C. The A/C input bumps the spark timing up when the A/C compressor clutch engages.