The Ford Barn

55blacktie · 12-11-2021, 03:03 PM

Does anyone have a K-code/w C4 automatic? If so, at what rpm are your WOT shifts?

5851a · 12-11-2021, 06:15 PM

Wish I could answer your question. Will follow to see if someone posts. The K codes have a special governor listed in the parts book. I tried to order one back in the day but was unavailable.

craig · 12-11-2021, 08:08 PM

I had a '66 K Mustang with a C4 years ago, at WOT it went to about 4800 rpms. Today you can get a governor kit for a C4 that includes a housing, springs and weights at Dynamic Racing Transmissions

55blacktie · 12-11-2021, 11:39 PM

Thanks, Craig.

I've been communicating with Matt (Dynamic Racing Transmissions) regarding their governor kit. It comes with 3 weights-11.5 grams, 12 grams, and 12.5 grams. The 12-gram weight provides WOT upshift at approximately 5800. Each .5 grams change will move the rpm up/down 200. Matt said that springs aren't included because they're not necessary. The housing normally comes with 12g weight installed, but you can request that the 11.5/12.5 be installed in the "Comments" section of the order form.

Gene F · 12-12-2021, 07:59 AM

Isn't a K usually a first generation mustang? 5,800 RPM is a lot. Especially in a car as light as that. So does the 1/2 gram more move the shift point up (higher RPM), or down?

55blacktie · 12-12-2021, 12:29 PM

Sponsored Links (Register now to hide all advertisements)

Lighter increases WOT shift point. The K-code engine wasn't exclusive to Mustangs, but most ended up there. It made max HP @ 6000 rpm.

rotorwrench · 12-12-2021, 01:07 PM

With springs being the same tension, it takes a lighter weight longer to react than a heavier one. Folks that sell governor mod kits likely just furnish them with new springs to insure proper operation as long as the springs are the correct tension or compression as originally intended.

Folks loved to put different torque converters and B&M shift kits in there back in the day. Most were wanting better street performance but some were drag racing with them for sure.

12-11-2021, 03:03 PM	#1
55blacktie Senior Member Join Date: Aug 2020 Posts: 442	289 K-Code Automatic Transmission Does anyone have a K-code/w C4 automatic? If so, at what rpm are your WOT shifts?

12-11-2021, 06:15 PM	#2
5851a Senior Member Join Date: Oct 2014 Location: NE Iowa Posts: 1,664	Re: 289 K-Code Automatic Transmission Wish I could answer your question. Will follow to see if someone posts. The K codes have a special governor listed in the parts book. I tried to order one back in the day but was unavailable.

12-11-2021, 08:08 PM	#3
craig Senior Member Join Date: May 2010 Location: The Inland Empire of Washington State Posts: 368	Re: 289 K-Code Automatic Transmission I had a '66 K Mustang with a C4 years ago, at WOT it went to about 4800 rpms. Today you can get a governor kit for a C4 that includes a housing, springs and weights at Dynamic Racing Transmissions

12-11-2021, 11:39 PM	#4
55blacktie Senior Member Join Date: Aug 2020 Posts: 442	Re: 289 K-Code Automatic Transmission Thanks, Craig. I've been communicating with Matt (Dynamic Racing Transmissions) regarding their governor kit. It comes with 3 weights-11.5 grams, 12 grams, and 12.5 grams. The 12-gram weight provides WOT upshift at approximately 5800. Each .5 grams change will move the rpm up/down 200. Matt said that springs aren't included because they're not necessary. The housing normally comes with 12g weight installed, but you can request that the 11.5/12.5 be installed in the "Comments" section of the order form.

12-12-2021, 07:59 AM	#5
Gene F Senior Member Join Date: Mar 2012 Location: Ohio Posts: 1,972	Re: 289 K-Code Automatic Transmission Isn't a K usually a first generation mustang? 5,800 RPM is a lot. Especially in a car as light as that. So does the 1/2 gram more move the shift point up (higher RPM), or down?

12-12-2021, 12:29 PM	#6
55blacktie Senior Member Join Date: Aug 2020 Posts: 442	Re: 289 K-Code Automatic Transmission Sponsored Links (Register now to hide all advertisements) Lighter increases WOT shift point. The K-code engine wasn't exclusive to Mustangs, but most ended up there. It made max HP @ 6000 rpm.

12-12-2021, 01:07 PM	#7
rotorwrench Senior Member Join Date: Jun 2010 Location: San Antonio, Texas Posts: 16,436	Re: 289 K-Code Automatic Transmission With springs being the same tension, it takes a lighter weight longer to react than a heavier one. Folks that sell governor mod kits likely just furnish them with new springs to insure proper operation as long as the springs are the correct tension or compression as originally intended. Folks loved to put different torque converters and B&M shift kits in there back in the day. Most were wanting better street performance but some were drag racing with them for sure.