transmission swap

[olds307 and 403]

The TCI is the lock up kit to lock and unlock the torque converter. It usually drops rpm 250 to 300 rpm. Is it 275/60R15 or 255/60R15 tires? Only a 50 rpm difference at speed. I get 2000 rpm at 60 and 2400 rpm at 70 mph with a 255/60R15 tire. I use this calculator, it includes the lock up torque converter.

Reference Manual: Chapter 3: Axles: RPM calculation

 

[olds307 and 403]

The modulator valve on the TH350 controls part throttle shifts, it has a vacuum line on it. The modulator doesn't exist on the 2004R.

 

[hoffa65]

So yah I was going for the 2200-2500 rpm range with OD running a 275/60/15 (27”)

I believe your correct on the frame extension but just Incase, Do you have link for the GeForce frame extension ? When you say “keep the lockup feature” are you referring to the torque converter, because I have no idea what one it has. I think it’s just a plain Jane factory 2004r. I included picture of torque label

at 70 you will be setting at about 2566 with a 27 inch tire with the 4:10's, 2200 if you run 3:73's
yes keep the lockup TC will lower the RPM more in cruse and the trans will run cooler. You will need a lockup controller like a TCI unit, a few differant ways to do it all depends on what you want and how deep your pockets are lol
That CBBD TC is a good one has a 2000-2500 stall speed and a 300 lbs clutch. It is similar to a Monty SS, Olds 442 or Olds HO TC. What is the number off the trans tag?

here is a link for the cross w/ extension https://www.crossmembers.com/produc...no-cutlass-grand-prix-regal-crossmember-400k/
here is the link for cross without extension if you frame already has it https://www.crossmembers.com/produc...ino-cutlass-grand-prix-regal-crossmember-400/

 

[Crazyc]

at 70 you will be setting at about 2566 with a 27 inch tire with the 4:10's, 2200 if you run 3:73's
yes keep the lockup TC will lower the RPM more in cruse and the trans will run cooler. You will need a lockup controller like a TCI unit, a few differant ways to do it all depends on what you want and how deep your pockets are lol
That CBBD TC is a good one has a 2000-2500 stall speed and a 300 lbs clutch. It is similar to a Monty SS, Olds 442 or Olds HO TC. What is the number off the trans tag?

here is a link for the cross w/ extension https://www.crossmembers.com/produc...no-cutlass-grand-prix-regal-crossmember-400k/
here is the link for cross without extension if you frame already has it https://www.crossmembers.com/produc...ino-cutlass-grand-prix-regal-crossmember-400/

I looked at the TCI kit looks very simple to install. Seems like I’ll have to get my carb Running correctly for the vacuum solenoid to work tho lol. So you said the TC is a good one, so that’s good news. What does the “stall” rpm mean to me and does that have any effect with the TCI lock up rpm ?

 

[Crazyc]

Btw my uncle has a 403 in his garage.

 

[olds307 and 403]

The 403 is a good choice but has the weaker bottom end. The new billet 4" stroker crank for the SBO makes a big difference, gives the 350 over 400 ci. What heads are on and what pistons were used in the rebuild on your 350? The flash stall is the rpm that your tach will jump to when you floor it. The lock up is just that, eliminates most of the slippage in the torque converter and is why the rpm drops.

 

[Longroof79]

I kind of got this rear end for a steal. ($150) and I don’t daily drive it, just if I wanted to go to a car show a hour or two away, I’d like to freeway it. And a t350 won’t cut it with this ratio.

Granted, the 4.10's would be fun on the street going from stoplight to stoplight, but any kind of distance driving, you're gonna hate 'em. If the car is going to see any track use, then I'd say keep them, otherwise sell them and find a desirable gear you could live with. Again, I think the drone from driving an hour or two each way is going to drive you mad.

 

[Crazyc]

Granted, the 4.10's would be fun on the street going from stoplight to stoplight, but any kind of distance driving, you're gonna hate 'em. If the car is going to see any track use, then I'd say keep them, otherwise sell them and find a desirable gear you could live with. Again, I think the drone from driving an hour or two each way is going to drive you mad.

Just crank the radio. Only would be like twice a year for a car show or two across state.

 

[Crazyc]

The 403 is a good choice but has the weaker bottom end. The new billet 4" stroker crank for the SBO makes a big difference, gives the 350 over 400 ci. What heads are on and what pistons were used in the rebuild on your 350? The flash stall is the rpm that your tach will jump to when you floor it. The lock up is just that, eliminates most of the slippage in the torque converter and is why the rpm drops.

I didn’t do the rebuild. But the guy that owned the motor before me was an executive at GM Detroit and had no expenses spared when doing it. I just remembered him rattling off cam specs and the heads have the #5 casting in the corner and he said it was bored out +0.10 I think. Or maybe it was .30 over not for sure. He never told me which pistons that I. remember. Has the aftermarket intake and a variety of other bolt on things.

 

[Longroof79]

Just crank the radio. Only would be like twice a year for a car show or two across state.

Well, if you think you can endure it, then go for it. It's your comfort level. 😵