6cyl Bellhousing interchange 66 vs 70?

[cboss70]

Hello, Sorry for the non-Shelby question but I figured someone would be able to help.  I have a 1966 mustang 6cly automatic car that was my fathers. After sitting for a year I recently had the transmission rebuilt because it had issues and when I got everything hooked up of course I get an engine knock. I have a 1970 Maverick 250 with its original c4 automatic attached to it. I know the spare engine ran good so I was thinking of mating my newly rebuilt 1966 transmission/torque converter/ flex plate/ bellhousing onto the 250.  The guy I got the engine from said that the earlier bellhousing would not fit onto the 70 engine (maybe he just wanted me to buy his transmission!).  Does anyone know if my 66 trans and parts are a direct bolt up onto this 70 250??

[OldGuy]

Your '66 transmission WON'T bolt to the new engine. The 250 cu. in. engine has the same bell housing bolt pattern as the 289 would have. That also means that the flex plate and torque converter do not bolt up either. You'll have to use the transmission that came with the 250.

Sorry for the bad news.

Frank

[Royce Peterson]

Your '66 transmission WON'T bolt to the new engine. The 250 cu. in. engine has the same bell housing bolt pattern as the 289 would have. That also means that the flex plate and torque converter do not bolt up either. You'll have to use the transmission that came with the 250.

Sorry for the bad news.

Frank

Pretty sure a 1966 Mustang would have a 200 CI six cylinder engine. Maybe that is what you meant. Anyway the early six cylinders used a different bolt pattern unique to them and it will not work with the 1970 era six which has the same bolt pattern as the 6 bolt 302 / 289 / 351 engines.

[OldGuy]

Your '66 transmission WON'T bolt to the new engine. The 250 cu. in. engine has the same bell housing bolt pattern as the 289 would have. That also means that the flex plate and torque converter do not bolt up either. You'll have to use the transmission that came with the 250.

Sorry for the bad news.

Frank

Pretty sure a 1966 Mustang would have a 200 CI six cylinder engine. Maybe that is what you meant. Anyway the early six cylinders used a different bolt pattern unique to them and it will not work with the 1970 era six which has the same bolt pattern as the 6 bolt 302 / 289 / 351 engines.

Royce, if cboss70 had a '70 200 cu.in. engine, he could bolt his C4 transmission to that engine. 1966 and later 200 cu.in. engines had an additional set of tapped bolt holes about 1.5 inches (don't hold me to that dimension) above the tapped bolt holes located in the center of the block. The reason that there is a dual pattern is that '66 and later manual transmission bell housings used the upper two holes for mounting to the block whereas the C4's used the lower tapped holes, as did '65 manual AND automatic transmissions. One of Ford's BETTER IDEAS (you tell me).

ALL versions of the 250 cu.in. engine used the larger V8 pattern as I described earlier.

I hope this helps (?)

Frank   

[Royce Peterson]

The C4 has a removable bell housing so worst case he would need to swap the bellhousings.

[OldGuy]

The C4 has a removable bell housing so worst case he would need to swap the bellhousings.

.........and torque converter and starter......

[Royce Peterson]

Yup.

[FL SAAC]

Hello, Sorry for the non-Shelby question but I figured someone would be able to help.  I have a 1966 mustang 6cly automatic car that was my fathers. After sitting for a year I recently had the transmission rebuilt because it had issues and when I got everything hooked up of course I get an engine knock. I have a 1970 Maverick 250 with its original c4 automatic attached to it. I know the spare engine ran good so I was thinking of mating my newly rebuilt 1966 transmission/torque converter/ flex plate/ bellhousing onto the 250.  The guy I got the engine from said that the earlier bellhousing would not fit onto the 70 engine (maybe he just wanted me to buy his transmission!).  Does anyone know if my 66 trans and parts are a direct bolt up onto this 70 250??

Unfortunately "the guy" is correct

[andyy]

Nope, sadly your '66 C4 won't directly bolt up to the '70 250 engine. The 250 uses the same larger bellhousing pattern as the V8s (289/302), while your original '66 200 had the small six-cylinder pattern. The torque converter and flexplate also won't match up.

Easiest route – just use the original C4 that came with the 250, it's already a match. Otherwise, you're looking at swapping bellhousing, converter, flexplate, and starter... a bit of a pain. Good on you for checking first before diving in!

[cboss70]

Thanks for everyone's feedback. I don't want to use the 70 C4 so based on the feedback I am going to:
1) Pull the 1966 engine/trans (validate it's still a 66 engine)
2) Use my rebuilt 66c4 "body" and new torque converter
3) But use the 70 250 bellhousing, flexplate, and 70 starter so it bolts up to my 1970 250 replacement engine.
4) Will make sure the depth of the 66 and 70 bellhousing are the same so there aren't any issues with spacing.
5) Will check the input shaft and hope it's the same length, size and splines.

In the scenario about just wondering if I can also use the 66 flex plate and then what starter would I need to use? Does that sound reasonable, or did I miss anything?