73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Chisholmcody on July 18, 2015, 12:29:55 am

Title: 250 to 350 conversion
Post by: Chisholmcody on July 18, 2015, 12:29:55 am
I just have a few questions on what parts need to be changed.

The first one is the motor mounts. I did a quick little search and haven't found the answer to my question. Are the 250 motor mounts the same as the 350 ones. And if they are is the only thing I have to do is to move them to the v8 position on the frame?

The second question- when I buy the crate motor can I run the oil pan it comes with or do I have to change it.

The third question- is the wiring  harness the same?


Sent from my iPad using Tapatalk
Title: Re: 250 to 350 conversion
Post by: zieg85 on July 18, 2015, 06:41:02 am
Good questions, I've not done a 250 to 350 switch in my 84 yet.  The previous 1967-72 the engine frame mounts would work but not sure of the 73 on ups.  The throttle cable is different.  You will need a V-8 shroud and radiator.  The PS pump, hoses and brackets are all wrong for the V-8.  Wiring is minimal, may have to be lengthened but I think everything should be long enough.
Title: Re: 250 to 350 conversion
Post by: Chisholmcody on July 18, 2015, 11:03:43 pm
for the throttle cable do i just buy one for a 78 truck with a 350?
Title: Re: 250 to 350 conversion
Post by: Irish_Alley on July 19, 2015, 07:12:57 am
for the throttle cable do i just buy one for a 78 truck with a 350?
that should do
Title: Re: 250 to 350 conversion
Post by: Chisholmcody on July 19, 2015, 01:53:28 pm
Alright thanks for the info guys hopefully I can do the swap before the end if the year


Sent from my iPhone using Tapatalk