305 to 350 swap (ive searched)

helihansen · 05-09-2008, 08:27 PM

I just read 9 pages of posts and couldnt seem to find the answer to my questions. I have a 90 k1500 with a dead 305. I have the ability to get a 350 out of a 95 G30. Can I just take the motor out and re-use the mounts, wiring and TB from my 305 without any problems? If not please let me know everything needed to swap a 95 350 into a 90 truck with a 305. Thanks

87c10slammer · 05-09-2008, 08:32 PM

they are assentially the same motors except for the tbi. you would need the tbi from the 350 and ecu but besides that i think thats it. i would wait for crab or jr to answer it though

helihansen · 05-09-2008, 08:33 PM

But the wiring harnesses are the same correct? Is it just plug and play?

87c10slammer · 05-09-2008, 08:35 PM

should be do the motors look simalir. same sensors in same location etc

chevyguy · 05-10-2008, 07:56 AM

You dont need to replcae the ECM, Its just a signal. It needs to be swapped going from V6 to V8 though. The throttle body will bolt right up also. If you dont have alot of extra performance he computer can compensate toe TBI enough so you can use the setup you already have. Drop it in, Straight plug and play.

Chevy_Finatic79 · 05-10-2008, 02:34 PM

I dont see why you wouldnt be able to to just pull the old motor buy new $10 motor mounts and drop in the 350 and hook back up all the wire connectors. The connectors can only go to the matching male and female plugs so you cant put them in the wrong spot. I think the only difference is the 95 has a EVAP canister pugre that you wont need anyway with the 90' wire harness.

the 4.3, 305,350,454 T.B.I. 87'-95' all use the 747 ECM

Sneakysportsman · 05-10-2008, 05:53 PM

It will all plug but a few things,
1. You will need a Prom for a 88-93 350 engine. Computer Chip.
2. You will have to reuse your 305 Throtle Body, Because 94-95 TBI units do not have a provision on the throttle valve lever for a detent cable (passing gear cable).
3. Motor mounts are the same.
4. The only other difference is the plugs on the throttle position sensor, but since you will not be using the 95 TB it's not a problem.

helihansen · 05-10-2008, 06:19 PM

Are the cc's actually different on the injectors or is it just the year of the units?

Sneakysportsman · 05-10-2008, 09:19 PM

Injectors are the same, length of spray is different in each ECM.

helihansen · 05-11-2008, 05:53 AM

Thanks! This whole chevy thing is REALLY easy. I am used to working on MUCH more complicated cars. If I put as much time into my truck as I do my wife's Audi...The truck would be capable of space travel.

05-09-2008, 08:27 PM	#1 (permalink)
helihansen Junior Member Join Date: May 2008 Posts: 4	305 to 350 swap (ive searched) I just read 9 pages of posts and couldnt seem to find the answer to my questions. I have a 90 k1500 with a dead 305. I have the ability to get a 350 out of a 95 G30. Can I just take the motor out and re-use the mounts, wiring and TB from my 305 without any problems? If not please let me know everything needed to swap a 95 350 into a 90 truck with a 305. Thanks

05-09-2008, 08:32 PM	#2 (permalink)
87c10slammer Senior Member Join Date: Mar 2008 Location: levittown pa Posts: 658	they are assentially the same motors except for the tbi. you would need the tbi from the 350 and ecu but besides that i think thats it. i would wait for crab or jr to answer it though __________________ HONDAS ARE LIKE ******! EVERY ONE HAS ONE 87 C10 SLAMMEd 400+hp 383 almost done. 00 GMC JIMMY wifes truck but my other toy**

05-09-2008, 08:33 PM	#3 (permalink)
helihansen Junior Member Join Date: May 2008 Posts: 4	swap But the wiring harnesses are the same correct? Is it just plug and play?

05-09-2008, 08:35 PM	#4 (permalink)
87c10slammer Senior Member Join Date: Mar 2008 Location: levittown pa Posts: 658	should be do the motors look simalir. same sensors in same location etc __________________ HONDAS ARE LIKE ******! EVERY ONE HAS ONE 87 C10 SLAMMEd 400+hp 383 almost done. 00 GMC JIMMY wifes truck but my other toy**

05-10-2008, 07:56 AM	#5 (permalink)
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,160	You dont need to replcae the ECM, Its just a signal. It needs to be swapped going from V6 to V8 though. The throttle body will bolt right up also. If you dont have alot of extra performance he computer can compensate toe TBI enough so you can use the setup you already have. Drop it in, Straight plug and play. __________________ When i die, i dont want to walk gracefully thu the pearly gates and turn in a unused body. i want to go sliding thru sideways and turn in a body that has been completely used up.

05-10-2008, 02:34 PM	#6 (permalink)
Chevy_Finatic79 Senior Member Join Date: Mar 2008 Location: Lincoln NE Posts: 436	I dont see why you wouldnt be able to to just pull the old motor buy new $10 motor mounts and drop in the 350 and hook back up all the wire connectors. The connectors can only go to the matching male and female plugs so you cant put them in the wrong spot. I think the only difference is the 95 has a EVAP canister pugre that you wont need anyway with the 90' wire harness. the 4.3, 305,350,454 T.B.I. 87'-95' all use the 747 ECM __________________ "She's gonna Freak when she see's my wheels" 85' Chevy C-10 Longbox (Rat) TBI 5.7 Liter/THM350 90' Chevy Suburban 4x4 TBI 350 Cu.In./700R4 http://www.truckforum.org/forums/truck-pictures-176.htm

05-10-2008, 05:53 PM	#7 (permalink)
Sneakysportsman Senior Member Join Date: Jun 2007 Posts: 199	It will all plug but a few things, 1. You will need a Prom for a 88-93 350 engine. Computer Chip. 2. You will have to reuse your 305 Throtle Body, Because 94-95 TBI units do not have a provision on the throttle valve lever for a detent cable (passing gear cable). 3. Motor mounts are the same. 4. The only other difference is the plugs on the throttle position sensor, but since you will not be using the 95 TB it's not a problem.

05-10-2008, 06:19 PM	#8 (permalink)
helihansen Junior Member Join Date: May 2008 Posts: 4	swap Are the cc's actually different on the injectors or is it just the year of the units?

05-10-2008, 09:19 PM	#9 (permalink)
Sneakysportsman Senior Member Join Date: Jun 2007 Posts: 199	Injectors are the same, length of spray is different in each ECM.

05-11-2008, 05:53 AM	#10 (permalink)
helihansen Junior Member Join Date: May 2008 Posts: 4	swap Thanks! This whole chevy thing is REALLY easy. I am used to working on MUCH more complicated cars. If I put as much time into my truck as I do my wife's Audi...The truck would be capable of space travel.

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