1988 305 - 1995 350

[Oldschool88]

I'm new here and I have a question. I have a 1988 GMC C1500 that had a 305. I recently swapped it for a 350 out of a 1995 Chevy K1500. This is my first swap so what do I need for a wiring harness? Will the harness match up with the truck as well? And is there anything else I need to do to get it running? I'm hoping the hard part is out of the way. Any info is much appreciated!

You must be registered for see images attach

 

[PlayingWithTBI]

As long as you use the Throttle Body from the 95 you should be good. You may need to get a TPS (Throttle Position Sensor) adapter cable. Then you'll need a chip (BCC) for a 350 and the same trans in your ECM. Everything else should bolt up.

TPS adapter, make sure the connectors look right
https://www.ebay.com/itm/233382109198?hash=item3656a8600e:g:gZgAAMXQ9y9SM1~r

Your chip should look like the one on the right in the plastic holder.

You must be registered for see images attach

 

[Nad_Yvalhosert]

Small block Chevy is small block Chevy.
Use the '88 wiring harness, use the '88 assessory drive, use the '88 exhaust.
There are only slight differences: Injector size, knock sensor
The distributor, coil, EGR, a/c will direct swap.

I swapped in a 355 in place of my 305, using the 305 TBI and 305 computer chip. Never had a fuel starvation issue, damn thing ran like a ***** date! The ECM learned to run the motor from the single O2 inputs, and 305 electronics.

 

[PlayingWithTBI]

Never had a fuel starvation issue, damn thing ran like a ***** date! The ECM learned to run the motor from the single O2 inputs, and 305 electronics.

I didn't think the ECM can add/subtract much more than 12% fuel in your INT/BLMs. Did you data log to see these? The 305 came with 51 LB/HR injectors where the 350 had 61LB/HR for a total of 20LB/HR more fuel. I would assume your VE tables were way off too unless you jacked up your fuel pressure?

 

[Nad_Yvalhosert]

Never did any other adjustments. Just drove it like I stole it. Plowed snow, pulled my 4 wheeler trailer, and to & from work for 3 years. Only saw a light gray discoloring on the plugs. Then I overheated the tranny plowing one winter...
I parked the ole girl out on my property, and replaced the truck with a '00 Denali. About 2 years later I got a Craigslist 700r4 and made her move under her own power again.