Andrew1980

I'm in the final planning stages of my 307 to 403 CCC swap on my 85 Toronado. If all goes according to plan I will do the swap in the spring. I've gotten a lot of information from the Performance 307 website. While most 403 swaps done away with the CCC carb and ECM distributor, im planning on keeping both to keep the stock TCC lockup.

It's my understanding that Christopher did the same swap on his 85 Riviera. According to the Performance 307 website, he can be reached on the OldsPower forum, but it appears that forum is no longer active. Is Christopher on this forum?

Thanks,

Andrew

Oldcoyote

I did that swap and tried to keep the CCC. It did not work. I replaced the carb and distributor with non CCC and everything worked fine.

There are several aftermarket ways to lock up the torque converter without the CCC.

You can save the money I wasted. Good luck.

Andrew1980

Thanks for the reply! What problems did you have with your CCC swap (check engine light codes / poor performance etc?) Did you make any changes to your 403 when you did the swap? I know that the CCC system doesn't like too cam or compression.


I have the 403 waiting on an engine stand and I'm still running the 307 in the car. I already added an extra temp sensor to the 403 for the ECM. Furthermore, I have modified the secondaries on the stock 307 carb to fully open and installed larger secondary metering rods and a "K" secondary hanger, which has significantly livened up the 307 :-)

Andrew1980

I'm keeping the 403 stock. Stock intake, heads, cam, and internals. Interestingly, GM used the same cam for the 78 403 as they did in the 307 until the mid 85 changeover to the roller cam. I'll also transplant the stock cast iron manifolds from my existing 307 (no headers available for the FWD 79-85 Toronado)


I already replaced the timing chain, water pump and fuel pump. I'm also upgrading to a high flow oil pump for PM since the engine has about 100K on it. The engine was sourced from a 78 Toronado that was running and driving when the engine was pulled. My hopes are that an Toronado sourced engine have been spared the abuse that many Trans Am sourced 403s experienced in their original application.

Oldcoyote

The CCC is a very primitive system, like a Commodore 64 computer.

I used a very mild Comp Cams 206 206. I don't know CR. Had 4a heads. The car had very poor performance, barely ran. Several mechanics looked at it. I changed distributor to non CCC but still no good. Changed carburetor to non CCC Q jet and everything was fine.

I used non lockup converter but there are switches available to lockup stock converter and they don't appear weird.

If the 403 doesn't like the CCC no one knows what to do. Why torture yourself?

I learned the hard way.

PS. I got a better cam two years later.

Andrew1980

Thank you for the information. A 206 206 cam is pretty darn mild. It's odd that the CCC carb didn't like the 403 engine with the 206 206 cam. Supposedly, the CCC carb / ECM system has no ability to know the displacement of the engine. It only measures manifold vacuum, RPM, O2 and coolant temp. On applications with the 7 pin distributor, it also measures and controls the advance curve.


The CCC carb can be richened up via the idle mixture adjustment screws once the anti-tamper caps are removed.


If the CCC carb doesn't work with some minimal effort following my 403 swap I will go with the non-ECM distributor and the non-CCC carb.


I did a little research and confirmed that B&M makes an adjustable speed controlled lockup torque converter kit that should work with the TH325-4R trans. The B&M part number is 70244. While it does not specifically list the TH325-4R as an application, it does list the TH200-4R as an application. Since the TH325-R4 and TH200-4R transmission use the exact same TCC lockup solenoid, there is no reason why the 70244 wouldn't work with the TH325-4R.


What cam did you ultimately install on your 403? Also did you end up using a non CCC carb that crosses to an original 403 application? What secondary hanger and secondary metering rods did you end up using with your setup?

Oldcoyote

I ultimately installed an Engle 18 20 custom ground on a 110. This is a 216 226. Very good fit however Cutlassefi had a bad experience with this cam, probably a later purchase on a 112.

I used a Carburetor Shop Qjet for a few years but it became a problem. Then I got a Jet Performance Q jet stage 2 which has been good for many years. I don't know if that would be the best choice today. Neither carb had a year designation. Don't believe the carbs had to be modified after installation.

As I've said before, you can probably get the CCC to work if it's your purpose in life.

Way too much information.