1964 Riv. question

If 1964 Riviera came equipped KX 2X4 motor and BS coded tranny what would chances be it to have a posi.??? Also due to the 2X4 motor would it be a 342 rear end?? THANKS. MIKE

Mike,

The KX engine was a single option offered for the first time in 1964. As far as I understand there were no "Gran Sport" or performance packages in '64 so the buyer who picked the KX engine would have to choose a larger rear end size (with or without limited slip), as it was not a packaged deal. A 3.07 open rear end was standard in 1964 with 3.23 and 3.42 as options. The rest of the car was basically a standard production '64. The first Gran Sport option came in '65 that offered the KX engine, a 3.42 with posi and larger exhausts. There was a separate ride and handling package with improve steering and beefed up suspension offered as well.

There are some people here who really know their Gran Sports so hopefully they can add to what I have described.

Although in '65 the dual-quad setup would have been stamped as the LX motor, as K denotes the '64 production year. There is a very good article on the topic here: http://rivowners.org/features/Ev_Stats/65gs/

If 1964 Riviera came equipped KX 2X4 motor and BS coded tranny what would chances be it to have a posi.??? Also due to the 2X4 motor would it be a 342 rear end?? THANKS. MIKE

Mike, Darren`s answer is right on. I`ll just add a few "half awake" morning comments...the `65 Super Wildcat is coded LX, there was no BS coded trans in `64 that I am aware of, I have encountered KX coded `64`s with both posi and open rearends and different gears but most seem to have a 3:07 posi. Many ratios were available but I have never encountered a `64 with a 3:42 gear so that, in my experience, would be very unusual. If you have a more specific question maybe we can be of more help,

Tom Mooney

Thanks for replies VERY HELPFUL.

So Tom if no BS CODED tranny in 64 would the 64 400 tranny with 2X4 set up have the different shifting points like the BS CODED TRANNY IN 65?? Thanks Mike

The '64 Trans is a different transmission than the '65. It's designated as an ST400 but in '64 it did not have the variable pitch torque converter that came out in '65 so it probably does not have the valve body for the firmer, higher rpm shifts. Chances are, as was said earlier, the only thing different on a '64 Riviera with the Super Wildcat engine option is just that and nothing more. No different transmission, no 3.42 posi, probably not even the larger diameter exhaust. Just the 2x4 setup - intake, carbs, air cleaner, distributor, and a/c bracket.

Ed

Thanks for the info. MUCH APPRECIATED. Mike

Thanks for the info. MUCH APPRECIATED. Mike

Mike, I did a little research to refresh my memory as this is an excellent question. Using only the trans codes can be misleading as to the particulars of each trans because there are many variables. For instance, in models which may be equipped with a console or column shift the trans code may be different just because the lever is different, not necessarily because there is an internal difference in the trans assembly. Also, car builds with differing rear end ratios can dictate a different trans code due to a different speedo gear, not relating to the sort of performance components you are interested in. I do have a source which specifies a unique trans code with the 2X4 425 coupled with a particular rear ratio but as stated above this could be more dependent on the rear gear ratio than the 2X4 equipment.

So, I turned to the `64 Buick parts book. Buick lists specific complete assembly part numbers which are different for 401 and 425 equipped models (with reference to console/column shift but without reference to rear gear ratio) but does not break out a specific 2X4 part number. Looking at the valve in the valve body Buick lists a different part number for 401 and 425 equipped cars but, again, nothing 2X4 specific. On to the governor...same governor for all ST 400 transmissions.

The specific component information is enough for me to believe, even with differing trans codes due to non performance variables, the performance characteristics of the `64 2X4 transmissions is no different than a single carb equipped 425. But the engineers were definitely playing games with the shift characteristics of the 401 versus 425 equipped models. Could this be due to different standard rear gear ratios for the 401 and 425 engines? Or have a direct relationship to sales pushing a "performance" gear with the larger 425 engine? I suspect so....but no doubt the engines have unique torque curves which would dictate a change in trans shift related components also. Hope this helps,

Tom Mooney

OK Lizotte: I purchased a rebuild kit from Transstar several years ago fior a 64 Riv I have. It was labeled a "Turbo-375/Turbo-400". I know about as much about transmissions as the man in the moon. My re- builder said the transmissions internally are very similar. The TH-375 in the 64 Riv with a 2 speed quadrant, the TH-400 in the 65 with the 3 speed quadrant. Incidentally, the quadrant is also known as a "Pernundal". Mitch