305 TBI to 350 TBI
I am looking to swap out my motor out of my 95 gmc truck. What will I need to change to make it work correctly? Injectors, and the ecm chip anything else?

I plan on getting a new crate motor.
Which motor would be the best to get the?
Truck version non roller cam p/n 12568758
or the 92-93 caprice motor p/n 12513151
anyone have specs on these 2 motor, like cam, cr, hp, torque, ect? as provided by GM

 

Knock sensors and ESTC modules are different.

Computer is the same, PROM is different.

Get the Goodwrench crate motor. I think it's like 240HP and a lot of torque. It's a great truck engine. Good on gas, runs 87 easy, very durable.

 

Best bet is to find the computer and pull everything connected to it harness and all.

 

There's no need to do that. You'll be spending money for a lot of stuff you don't need. I already did this swap. Change the ESTC module, knock sensor, & PROM. Everything else is the same betwen the 305 and the 350 TBI motors.

 

I'm looking to swap a L05 in place of my L03 and my question is, what exactly do I need to do this? Can I use my existing TBI? My wiring harness? I know I have to change the computer, but will everything just bolt in place? Me and my dad are looking to make this a weekend project starting Friday night and get ready for work on Monday morning. He's going to work on the suspension and brakes while I work on the wiring and hook-ups on the new engine. Thanks for your help guys! I greatly appreciate the expert advice!

 

Externally, the LO5 is exactly the same as the LO3 so you can use the same harness and don't need to change the "computer" just the chip in the computer. Look for a prom chip for a Caprice 9C1 car. Then just get a 350 knock sensor and esc module from the caprice. You will also want to get some bigger injectors.

 

Thanks for your input!

How big should the injectors be? And where would I find these parts, can you provide part numbers or can I just get these off the internet?

 

Well if you go with the Caprice prom chip you should go with the caprice injectors they are 65# injectors and the color codes on the tops on the injectors are yellow and brown. Check junkyards and ebay for injectors or a full TBI unit. If you can't get a hold of the 65's you can get 55#'ers from a 350 TBI truck orange/black with a little more fuel pressure.

You may also need a new fuel pump, they tend to die out if they have to keep decent pressure up for long with a bigger engine. Look into the Walbro 255.