1984 gmc 3500 new process540 swap

[Rogerhsr]

Using the original would be best. Then use the original transmission mount (replace with new one if worn), and build a bracket from mount to the transmission brace. Seriously pursue the better dual mounting bracket/ seal cover. Well worth a couple hundred bucks.

Because you are doing it custom, inspect if frequently: daily for the first 2 weeks. Then monthly for the first two years. Then every normal service. Sounds excessive, I know. But better safe than sorry. Caught early you plan a repair, missed 1 day late involves tow trucks and possibly damage to even other vehicles.

 

[Will L.]

@Rogerhsr
You quoted my last post but no comment came through.
Any questions?

 

[Rogerhsr]

The guy I got the transmission from said that bracket had a brake cable attached to it for the brake so I’m not sure

 

[Will L.]

I am going off memory from a lot of years ago. I could be confusing this with another transmission. But I guarantee not supporting the transmission weight, any transmission behind a 6.5, will not leave the block without damage.

 

[Rogerhsr]

I am going off memory from a lot of years ago. I could be confusing this with another transmission. But I guarantee not supporting the transmission weight, any transmission behind a 6.5, will not leave the block without damage.

 

[Rogerhsr]

I agree

 

[MrMarty51]

Is Your transmission one with overdrive ?
If not it would be great to upgrade to a five speed.

 

[Rogerhsr]

Is Your transmission one with overdrive ?
If not it would be great to upgrade to a five speed.

This new process is a 5 speed

 

[Will L.]

Do you know which gearing yours has? Many were really low geared and 5th was 1:1
So like a 3 speed with 2 super lower than normal. That is the configuration most liked them for. Back before there was an option of an atlas transfer case with massive low range, many guys got this transmission for off road or if 2wd and they had to tow really heavy stuff but never over 55 mph it was good.

Kinda wondering why you are making this change, actually instead of something from the late 70’s to now. This is really a late 60’s early 70’s transmission. They were around in the 50’s but late 60’s was when they got used the most

Have a pto you need in the truck?

 

[Rogerhsr]

It’s a Holmes wrecker I just wanna be able to run 55mph it’s gotta be better then the sm465 it kicks the rpm’s up to high in high gear

 

[Rogerhsr]

And yes it does have a pto

 

[EWC]

How about some pictures of the sm465 and cross member that came out of the truck .

 

[Rogerhsr]

I will get them tomorrow

 

[Rogerhsr]

This is what I have