Bought a 1949 F1 a while back but trans crapped out after I got it home and drove maybe 100 yards so there it sat. Finally have some time and a little project cash so time to get it fixed. Anyway, PO swapped in a 300 from a '66 and the C4 is a '73 or later. Would really appreciate confirmation on the info I've been able to dig up before I start buying parts. Believe the flexplate is 164 tooth. The 300 and the V8 look to be different, the 8 is external balance so can't swap. The stock torque converter looks to be the same on the 6 and the 8 C4 trans. The trans bolt pattern looks the same as the Windsor SBF. Right now the truck has a pretty bad vibration at idle that gets worse with RPM so guessing I have a bad TC or the wrong flexplate. Am going to fire it up once I get the trans pulled and see if the vibration goes away. Balancer isn't wobbling so think that's okay. Am getting close on my Chev 3100 so hope to get the Ford roadworthy so my wife can drive it when we go to events this summer. Chev is 3 on the tree so she's a hard pass on driving that one.
You are correct. The 300 shares the same bellhousing bolt pattern as the Windsor V8's. However, because of the fundamental balance differences between an inline-6 and a V8, everything else is different. I would skip the C4 and drop an AOD in it instead, but either way, getting the correct flex plate and convertor will be critical.
I believe all 300 6's are neutral balanced so if a v8 flexplate was used, it would be counterbalanced.
X2 the bellhousing bolt pattern of the 300 is same as SBF Windsor style V8s. Not a Ford expert, but I would say the flexplate should be ordered to match the engine, and the torque converter should match the trans, although I am not aware of any differences in C4 spline counts or spacing that changes through the years.
I have vehicles using a 300 six and a C4. It is a very good combination in my lightweight cars. The 300 is indeed neutral balanced while the V8s are externally balanced with counterweights on the flywheel and the damper (except the BOSS 302 V8s). If your bellhousing is for a 164 tooth flywheel it will bolt up directly to the 300, with the starter hole in the correct location. [SIDE BAR: It is also possible to use the smaller 157 tooth flywheel but that requires a smaller C4 bell, somewhat rarer, from a Granada 250 six, along with the block plate and flywheel. If you have room in the tunnel just use the 164T bell.] Spline count on the C4 varried by year. Here's a summary. 1964-1969: 24 splines on both ends of the input shaft (.788" diameter). Castings: C4, C5, C6 (1964-1966), C7, C8, C9 (1967-1969). 1970: 26 splines on both ends of the input shaft (.839" diameter). Castings: D0. 1971-1981: 26 splines at the torque converter end and 24 splines at the forward drum end (clutch hub) (.839" diameter). Castings: D1, D2, D3, D4, D5, D6, D7, D8, D9. Good luck with your project.
Appreciate the help! I have a 302 and an AOD still in a donor car but more of a project than I can tackle right now.
Hey Frenchtown, are the output shafts the same on the pre-70 C4s and the later trans? Found one from a 1965 Mustang that looks good.
I think outputs are the same . I’m not 100% sure but I think you can remove the weight from 302 flex plate and will be fine on 300 as long as teeth count are the same . Research this a bit , I can fully recall
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