Swap Help!!!!

[Smitch320]

Hey Fellas,

New Here, I have a question.

Currently the truck I bought to use as a hunting/work truck is a 1986 K10 with a 262 4.3L and a Muncie SM465.

The motor needs rebuilding and I have just decided to drop a 350 in it, I have been looking at a few on Jegs.com and summit.

http://www.jegs.com/i/Chevrolet-Performance/809/10067353K1/10002/-1?parentProductId=

It says that it only fits up to 85- why is this? If this is true it has somewhat crushed my plans of the swap.

 

[RetroC10Sport]

It will fit.

 

[Smitch320]

Awesome, I am not a mechanic by any means, but I have been fooling around with cars for a few years.

Retro, any idea as to why they would not advertise it fitting a 86?

anyways, thanks for the response.

 

[RetroC10Sport]

My guess is that it has to do with emissions and possibly the exhaust manifolds which you would be changing anyway. But I'm just spitballing there. Sure someone else can chime in too.

 

[Smitch320]

Anybody else, feel free to chime in

 

[Stroked]

It's something to do with emissions or being 50 state legal. Almost every crate motor I've looked at is like that.


Sent from my iPhone 4s using Tapatalk

 

[87sierra]

my buddy just put that same motor in his 1986 gmc 3/4ton 4x4 and it went in pretty easy
the only reason they say it goes up to 1985 is because of emissions that were put on in 86

 

[Smitch320]

What did he have in before?

 

[Jims86]

My guess is that it has to do with emissions and possibly the exhaust manifolds which you would be changing anyway. But I'm just spitballing there. Sure someone else can chime in too.

the 86 v8 was specific for 86 only, as it is a one piece rear main seal, but still has the early parimeter bolt valve cover heads.
You will need an 85 or earlier flexplate, but all of your 4.3 accessories should fit. Has nothing to do with emissions.

 

[HotRodPC]

the 86 v8 was specific for 86 only, as it is a one piece rear main seal, but still has the early parimeter bolt valve cover heads.
You will need an 85 or earlier flexplate, but all of your 4.3 accessories should fit. Has nothing to do with emissions.

This is the CORRECT Answer. The motor will fit and work in your truck fine. Also along with the one and 2 piece rear main difference, I do believe the oil dipstick changed sides of the motor too. The one beauty of those GM Crate motors that are Heche En Mexico, is that they have provisions to put the dipstick on either side. It should come with, or you will need to get, a tiny freeze plug type looking thing to plug off the side you're not going use, or run 2 dipsticks.

 

[Smitch320]

Does that mean the flex plate from my 4.3 will fit? Or would I need to buy aftermarket?


Thanks for all of the help guys

 

[HotRodPC]

Does that mean the flex plate from my 4.3 will fit? Or would I need to buy aftermarket?


Thanks for all of the help guys

Unless someone knows of some reason I don't, it will fit and work. A 4.3 is a 5.7 with 2 cylinders cut off the back.

DOH, and now I guess I better back up. You'd be going from a 1pc rear main motor to a 2pc rear main motor. Now I'm not positive if there is a difference thare or not. I don't think so IIRC.

 

[kleedus]

the motor mounts are different as well if i remember right

i have a 4.3 from a 4x4 86 i wanted to put it in a 2 wheel drive just have not done it yet

for some reason i am thinking the motor mountbrackets that bolt to the frame are different

i saved the ones from the truck that i pulled the 4.3 from if i get the chance i will go look

if they are different all you will need to do is get the v8 mounts and bolt them in i may have a set if needed

and yes 86 was a change over year for the rear main seal other then the flywheel everything else should swap over

you will just need a flywheel from a 86 and up 350 1 peice rear main

 

[89Suburban]

Aw man, a 4.3, stick shifter, 1/2 ton, foh-by. That's neat.

 

[Smitch320]

Flex and Flywheel the same thing?

Sorry guys im still learning