RE: [Chrysler300] 1963-1964 300J-K - 150mph Speedo
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RE: [Chrysler300] 1963-1964 300J-K - 150mph Speedo

Thanks, Carl.


All very clear and well-presented.


Just for the exercise, I used my handy-dandy speedo pinion/differential ratio spreadsheet on the 3.91 axle.  Turns out the speed in direct drive at 6,000 RPM would “only” be 128.3 MPH on 8.50x14’s.  A 22 or 23-tooth speedo pinion would each provide +/- 2% speedometer readings (respectively).  The slightly-larger diameter 7.60 x 15’s on the J’s would provide about 2% higher speed at the same engine RPM and tranny ratio.


If the 1963 3-speed stick had a 1.49 second gear, 6,000 RPM on the engine would give one 86.1 MPH in second gear.  Much more a dragster than a land-speed record contender.  The 1.39 third gear in a four-speed would get one 92.3 MPH @ 6,000 RPM.  It would be interesting to hear from those High-T guys who drag-raced their 4-speed 300K’s as to whether they had to shift to fourth in the quarter mile.  I’m guessing not.  I would guess the three-speed manual would have had to be shifted to high.  The 3-speed TorqueFlite with the 1.45 second gear would give one 88.5 MPH in second gear at 6,000 RPM—may or may not need that slam-bang 2-3 shift near the end of the quarter.


The current five to ten-speed transmissions certainly offer the potential of keeping an engine at optimum speed and torque levels for desired results—be it emissions or performance.


I’m seeking another level of precision and could use the actual number of teeth on drive and driven gears in the various trannys.  I have them for the various differentials and speedometer pinions.  The table below is from the 1964 Service Manual.






Direct drive: All Transmissions


3rd gear:  4-Speed


2nd gear:  TorqueFlite


2nd gear:  HD 3-Speed


2nd gear: 4-Speed


1st gear:  TorqueFlite


1st gear:  HD 3-Speed


1st gear:  4-Speed



Best wishes for a good old Iowa Christmas.


Rich Barber

Iowa Expatriate


From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Carl cbilter@xxxxxxxxx [Chrysler300]
Sent: Tuesday, December 05, 2017 9:31 AM
To: 'Chrysler 300 List' <Chrysler300@xxxxxxxxxxxxxxx>
Subject: RE: [Chrysler300] 1963-1964 300J-K - 150mph Speedo



Rich and all:

Regarding 1963, all Js had the 150 speedo in the US and had tachometers. They were not options on other 1963 Chryslers. 1963 300 Sport series cars (Pacesetter or not; two door and four door) with an optional console came with a compass instead of a tach when equipped with TorqueFlite. The console required the bucket seat option obviously. And yes Virginia, one could order bucket seats and a console in a four door Sport series 300. The compass probably worked OK when new – except on Sport series 300s that came with the standard 3 speed stick transmission. Due to calibration problems with the compass, a very early production running change was made where the bucket seats and console could no longer be ordered with the manual transmission on the Sport series. This didn’t apply to the J, since it was equipped with a tach. The seven 3 speed stick Js produced had a console and tach. The 3 speed stick J was a no cost option that was offered as a production running change early in the model year. It came with a 3.91 rear end vs. the 3.23 rear end that was standard on the TorqueFlite J. It may had had a different speedo pinion gear.

Re. 1964 I defer to the K experts, Chris the “K maniac” or Don Cole, but my understanding is that all Ks in the US had the 120 speedo and only the 4 speed Ks had the tach. TorqueFlite Ks came with the vacuum/performance gauge in the console.

Regarding actual top speed factory stock performance (as opposed to theoretical or anecdotal tall tales), I have correspondence from bona fide expert Burt Bouwkamp that the J was a true 140 mph car off the showroom floor, mostly a result of the headers, short rams, and solid lifters. As opposed to a cross ram hydraulic lifter F or G with log exhaust manifolds and long rams which was basically a 130 mph car according to Burt (not counting the F Special 4 speed, which was notably faster). So to gain an extra true 10 mph at those speeds means that the J had substantially more high end power (and less weight to move). This bears out when looking at the period test results. And especially compared to an H which also had solid lifters but not the headers or short rams. 0-60 in an H is about the same as a J, maybe even slightly faster, but 0-100 mph in a J is a full 4 seconds faster than in a H! And, it could be done in a quarter mile as well. Ram K hardtop should be similar depending on weight of car. A ram K with no options and the 14 inch tires (vs. J 15 inch) might have weighed about the same as a J, but most Ks (I think) weighed a little more than the J. Ram K convertible would be slower (more weight).

Now, imagine a 3 speed stick K with the 3.91 rear end in the hands of a good driver. Only seven were built and none are known to still exist; so we can only speculate on performance. But, I suspect, quarter mile times would have been sub 15 seconds and over 100 mph.

Please note: I am talking about factory stock which includes rather restrictive factory mufflers. Aftermarket mods can make a big difference. The stock J./ramK cam was pretty mild actually.

Carl Bilter

From: 'Rich Barber' c300@xxxxxxx [Chrysler300]
Sent: Sunday, December 3, 2017 8:24 PM
To: 'Matt Allyn'; 'Chrysler300'
Subject: [Chrysler300] 1963-1964 300J-K - 150mph Speedo

Historical/technical questions for the J-K crowd:
• Did all 300-J’s have the 150 mph speedometers and tachometers?
• Were the 150 mph speedometers and/or the tachometers an option on any other 1963 Chryslers?  Maybe special order?
• Did any of the 300-K’s or any other 1964 Chrysler (including police cars) have standard or optional 150-mph speedometers and/or tachometers?  Seems I had heard or read that all 30-K’s with four-speeds had tach’s instead of vacuum/performance gauges.
• Did any 1963 or 1964 Chrysler with a 150-mph speedometer have a different speedometer pinion gear—or were all calibrated to the standard 1,000 RPM @ 60 mph?
• I do recall that the 1963 300 Sport Pace Cars had compasses mounted in the consoles.  Was that option offered on any other ’63 or ’64 and did those work OK?
I just ran some calc’s for 8.50 x 14 tires (28.10” OD); no tire-to-road slippage or wiggle-woggle, 3.23 differential ratio; 150 MPH requires 5,797 RPM at the tail shaft.  140 MPH= 5,411 RPM.  Possible for a J or K? 
Rich Barber
Brentwood, CA
From: Chrysler300@xxxxxxxxxxxxxxx [mailto:Chrysler300@xxxxxxxxxxxxxxx] On Behalf Of Matt Allyn allynentertainment@xxxxxxxxx [Chrysler300]
Sent: Sunday, December 03, 2017 3:27 PM
To: Chrysler300 <chrysler300@xxxxxxxxxxxxxxx>
Subject: [Chrysler300] 1962 300H - 150mph Speedo
Anyone have a 150mph speedometer for sale for my 1962 300H?
I have all other Astradome parts & pieces; but only have a 120mph speedo.
Matt Allyn

[Non-text portions of this message have been removed]


Posted by: "Rich Barber" <c300@xxxxxxx>

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