BUILD THREAD Motor Swap, Transmission and Torque Converter Swap, and Rear End Upgrade...

[Rt Jam]

This thread seemed to have gone for a sh*t.

I just came here to throw some advice to the mix. You have to know the pros and cons of each decision.

An 8.5 is literally a bolt in but supply and demand has priced these way out of reach for a hot rod. These can be reserved for Grand Nationals and 442, which you will not find in a junkyard. Then add a rebuild to that figure.
I sold mine for $2500 a year ago so keep that in mind if you chose to pursue that route. The sale almost paid for a 12 bolt GM from Moser, a brand new bolt it.

Not a fan of Ford 9" for a 12 sec street car. They are not as efficient and have no room for a decent size differential. These are great for single digit cars with a spool.

Many choices on transmissions. A 4L60E is a great transmission for that power level. It only requires a controller, one plug.

The last Vortecs from a truck like a 96-98 are rollers. These are great swap engines but will not have the hp like an LS which is an entirely different topic.

 

[UC645]

UC645 the 4L60E is an electronic version of the 700R4. Pretty much same mechanical internals just electronically controlled solenoids that move the fluid.

They can fail mechanically just like a 700 but also if you don't have the tune correctly on them you can kill one that way too. Nice extra bonus of electronics.

Not trying to be the “Well Aktually” guy, but:

Yeah. GM corporate is a complete mess. And that’s another reason why I hate those transmissions, on top of the truck rated first gear.

 

[UC645]

I just came here to throw some advice to the mix. You have to know the pros and cons of each decision.

An 8.5 is literally a bolt in but supply and demand has priced these way out of reach for a hot rod. These can be reserved for Grand Nationals and 442, which you will not find in a junkyard. Then add a rebuild to that figure.
I sold mine for $2500 a year ago so keep that in mind if you chose to pursue that route. The sale almost paid for a 12 bolt GM from Moser, a brand new bolt it.

Not a fan of Ford 9" for a 12 sec street car. They are not as efficient and have no room for a decent size differential. These are great for single digit cars with a spool.

Many choices on transmissions. A 4L60E is a great transmission for that power level. It only requires a controller, one plug.

The last Vortecs from a truck like a 96-98 are rollers. These are great swap engines but will not have the hp like an LS which is an entirely different topic.

Thanks for that clarification, couldn’t remember the accurate years on roller blocks.

 

[Built6spdMCSS]

Not trying to be the “Well Aktually” guy, but:
View attachment 228736
Yeah. GM corporate is a complete mess. And that’s another reason why I hate those transmissions, on top of the truck rated first gear.

I know what the 4L60 is, why I added the E in to my post and elaborated with some tech info.

The one difference I've seen if I remember right with the 700R4 and the 4L60 is it has an electronic speed sensor where the 700R4 is still cable. I could be off on that but it's something really small like that.

 

[Built6spdMCSS]

Not a fan of Ford 9" for a 12 sec street car. They are not as efficient and have no room for a decent size differential. These are great for single digit cars with a spool.

Manual cars with power the 9" is the way to go, 8.5 or an 8.8 will fall apart over time. I don't think I'd make it out of my driveway with a built 7.5..🤣

Not sure what you mean by the "no room" part, like in the back of the car or the actual differential in the axle housing?

 

[UC645]

I know what the 4L60 is, why I added the E in to my post and elaborated with some tech info.

The one difference I've seen if I remember right with the 700R4 and the 4L60 is it has an electronic speed sensor where the 700R4 is still cable. I could be off on that but it's something really small like that.

Ah, I got you now.

Still, I’ve got some info rattling around my head that when GM switched the designations, they started embossing model numbers on the transmission cases. Which just adds more confusion for no reason.

As far as the sensor vs cable, I’m not sure. I had a 90 GMC Sierra that should have had a 60, but the speedo in it was still cable driven, IIRC. Might be worth a junkyard dive to confirm.

 

[Built6spdMCSS]

Yea that or Google, Google doesn't cost gas money haha just have to find the correct info.

Right there in the early 90s was a whole bunch of one year only stuff because of going electronic. Some really hard to find parts in that era.

 

[bruisedbanana79]

Blueprint Engine
Gearstar 700-R4
Currie rear end

Problem solved for a small fee of $15K

 

[mikester]

I tend to agree with the option of a crate motor. I used one for my wagon. 350/330HP and went right in. No muss, no fuss. Plus it came with a warranty. Honestly, it took less than a week to get from my local Chevy dealer. Came with everything. Starter, carb, AC parts. EVERYTHING. No worries about having stuff machined and built. I went that route with the 406 for my 81 and the crate motor was cheaper. Maybe consider that. More HP then youre going to need

 

[Rt Jam]

Manual cars with power the 9" is the way to go, 8.5 or an 8.8 will fall apart over time. I don't think I'd make it out of my driveway with a built 7.5..🤣

Not sure what you mean by the "no room" part, like in the back of the car or the actual differential in the axle housing?

First of all, I'm not bashing the Ford 9". The internet has already pushed them up to a high place because they are seen under many quick cars. The advantages are many and I agree with most of them.

The only part that is not mentioned is something that I've noticed when choosing a differential for the street.
One thing that gives a 9" it's strength is the pocket bearing or rear bearing behind the pinion gear. Where that bearing lives is the same space a differential lives. No problem for an open or spool but if you want a differential you are forced to have one with tiny clutches or puny helical gears.

Street cars need a differential, no spools for the street. If a single digit car needs it. I understand but a mild build does not need a rear that is a bit higher in drag due to it's pinion being so low that I believe it's no longer truly a ring and pinion, it should be referred to as a worm drive.

Trying to explain this to someone who wants to argue carb vs efi if different. I felt like you deserved a technical explanation and I've included a pic of the typical size diff for a Dana 60, GM 12 bolt, 8.5, 8.8 vs a Ford 9" on the right.