Yenko turbo 400 speedo adaptor

[Kurt S]

I politely disagree with Ed's statement that all 4.10 manual cars had an adaptor. [img]/ubbthreads/images/graemlins/smile.gif[/img]
As I said up above, there were 2 different Muncies (with 2 different part #'s) with 2 different size speedo drive gears. One needed the adaptor with a 4.10 gear, one didn't. Usage was apparently driven by availability. So, it's a crap shoot if a manual / 4.10 car had an adaptor originally.
Don't think it's on the CRG site, but we've discussed it at length. Ask Jerry MacNeish, he's rebuilt hundreds of these trans' and is very familiar with the issue. And I have broadcast sheets that clearly show 4.10 cars without the adaptor.
I'm pretty sure all 4.56 and 4.88 gears had the adaptors.

No idea on the auto.

[Ed Cunneen]

Kurt,
My information relates specifically to COPO's. The chart on my website which shows speedo adapters relating to COPO's is a reference that came directly from the COPO build orders. My interpretation of this is that all specifically referenced COPO's had this reducer. Perhaps it is because they all were ordered with the same type of transmission. I then listed the chart that came directly from Chevrolet parts for COPO's that had 4-speeds with certain tire combinations. Since these combinations were RPO's and not deviations, it was not necessary for Chevrolet to list them in the COPO build order. I have never encountered a variation from the above, but if we find exceptions, I would be happy to add them to my site.

[Kurt S]

Thanks for mentioning the source of the info.
I'll defer to you as I don't have any L72 chassis broadcast sheets nor have I looked at *that* many L72's. [img]/ubbthreads/images/graemlins/smile.gif[/img]

BTW, I've found some of the factory info can be in 'error'. Only one build option will be listed, though another build option/combo is possible.