olds 307 and 403

I need to find a 2WD core that they don't want $1500 for locally. I have the Terminator X Max with controller and wiring harness. Does the crossmember need modified? Looks like a piece added on. I know a different converter is needed, something mid 2000's stall, looking at least $500. I plan getting the Holley digital dash for the speedometer. Anyone know the drive shaft length for a 70 Cutlass S with the 12 bolt O axle along with the needed U joints?

olds_freak

Anything over $150 for a CORE is robbery. If you're mechanically inclined and can follow instructions, you can rebuild it yourself. You'll need an aftermarket crossmember to make it easy. The stock one can be used technically, but it has to be slid all the way back and it's a pain to get in and out. Like a real pain.

As for the converter, you can use a stock one, but an upgrade here is always a plus. Don't cheap out on a converter. A nice lockup converter for a 4L80E is going to be at or near a grand.

The driveshaft will have to be measured once you get it all installed in the car. You'll also need an adapter plate, a dipstick, shift linkage, and the ability to rework your cooling lines. I've done this swap into an A-Body. It's tight, but there is room. It's the best trans out there for the normal guy that's super strong and has OD.

joe_padavano

Floorpan in a 70 Cutlass and the 69 Chevelle in this article are the same. The only difference will be the thickness of the adapter plate that pushes the trans back about 5/8".

olds 307 and 403

Thanks guys. Yeah I saw the article. Moving the stock crossmember back and forth is a royal pain. I am hoping for an add a shift kit and go TH4L80E. I realize the really good converters are grand, will see what I can stomach, looks like $600 minimum, only will only need mid 2000's. I assume there is probably a difference between the O axle I am using and the chebby rear end in the Chevelle for drive shaft length. Looks like it will be in the 54 to 55" range. Either way I plan on doing the O axle gear swap, new posi and hopefully find a 4L80E to swap in the Winter of 2024.

joe_padavano

Yes, there's a difference between the Type O and Chevy rear axles as far as driveshaft length is concerned, plus the added thickness of the adapter plate.

rfpowerdude

I need to do this too, but I wanna do it into the silver car. This sticky article on the G-body forum (https://gbodyforum.com/threads/so-yo...uccesses.65800) is great except it's for a Chevy mated to the trans. I need to figure out who makes what to mate it to an Olds. And fit in a Gbody.

joe_padavano

I'm gonna go out on a limb here and suggest that asking about a G-body in a thread about a 70 Cutlass S might not be the best way to get that answer...

rfpowerdude

While I agree with ya Joe, I am acquainted with the OP on the Gbody forum and he has a thread going on there too about his '70 (in the Off Topic subforum). I guess I really am posting about just the mating of the two together, offsets, torque converters, flexplates, companies that make stuff, etc. Not so much the Gbod side.

If OP feels this is inappropriate, we can take it to the thread on the other forum. This was, again, more about mating the two successfully.

olds 307 and 403

No problem, there isn't squat out there, at least Olds specific, anyways. I will update this thread, if I can find a used 2wd 4L80E for less than $1100. I should have grabbed them when they were $500, which is what I want to pay for a used, unknown transmission.

rfpowerdude

Cool, I have checked from here to Tampa and there isn't sheet here either. Not even anything for sale. Well, there are two. One is a 4WD app and the other is in Tampa and he wants $2100 for it. Sheesh.

olds 307 and 403

The 4WD ones I can find for $500. The 2WD, last two I have found were $1100 and $1500. A GM reman sticker apparently makes it gold. It could have 300,000 since then for all they know.

rfpowerdude

I wonder how much one would be at an LKQ yard...