Technical please help...Ford inline 300 with C-4 trans bolt-up in t-bucket

Hi...I'm new to this, so please forgive my fault if I've done this question wrong.
--------I have a 1914 Oldsmobile roadster t-bucket, that I've found I have a serious question about...namely, that I have a 1978 Ford 300 inline 6, that runs excellent. The question I have, is that I have a 1966 mustang c-4 that is also excellent, but with all the different flexplate matters, i'm not sure 'how' to match them up without doing damage to my engine. They both match-up fine with bolts holes, but I've read that if the engine has a 164 tooth flexplate (and torque converter that came bolted onto the engine when purchased) that major changes must apply to adapt a smaller c-4.....and now I have bought a good smaller c-4 with a 157 tooth flexplate (with torque convertor attached)-----can I take off the old 164 tooth flexplate and bolt on the 'newly bought' transmission with the 157 tooth, with attached flexplate and torque converter with the smaller bellhousing without any problems?-----or do I have to change directions with my drivetrain?...I'm not sure if I should use a 28oz. or 50oz flexplate...the 'new' c-4 I just bought has a 'smaller' torque converter and 157 tooth flexplate attached. I "don't'' have a 164 tooth bellhousing at all....the only 'complete' transmission I have is the 157 tooth 66' mustange tranny... I am on a limited budget, and trying to do it right.
I read that v-8's such as 289, and 302's ...have to have a different crank, harmonic balancer, etc...switched to do this....does that ''also'' apply to my 1978 Ford inline 300???? Someone like myself, with a 'learn on the job' qualifications as a 1st timer, I'm not sure where to take this now....I don't want to ruin anything beyond repair. Any help would surely be most welcome....thanks so much.....Rai

 

The 300 is internally balanced, you do not want a weight on the flexplate. The flexplate, starter, bellhousing, spacer plate, transmission, and converter must all match each other, The 66-up 6 bolt bellhousing stuff should fit the back of the 300.

I don't know for sure if what you have will work....you're going to have to look at it and see.

 

Yes, you need a zero balance flexplate, otherwise all your 1966 157 tooth C-4 pieces should fit the 300. No issues with the stock 300 front harmonic balancer.

 

thanks so much for answering....I was really concerned about the stuff I read on other ford engines with that darn harmonic balancer and internal engine operations. I have all the stuff with the 66 c-4 included and ready to go, and I've ordered a new zero balance flexplate...everything lines up fine, and was just concerned about the 'smaller' c-4 not working properly where the engine had a bigger flexplate attached when I bought it....I appreciate your help here big-time....thanks....Rai

 

As long as it is a zero flex plate you are ok , big or small

 

And the correct starter pinion gear..

 

Is that Mustang C4 From small six? If so there isn't a flex plate in the world that will help your situation, as the 300 shares the same bell housing pattern as the small blocks, and the smaller Falcon six doesn't. A V8/ 300 type bell housing can be swapped onto the trans, but more stuff needs to change. Better to find a V8 trans.

 

This mustang c-4 is out of a 289 v8 Ford....and it was the V8 factor that had me concerned, with all the balancing needing to continue....but I'm assuming that since it was a v8 tranny, then it should bolt on with no serious headaches onto the inline 300 which is internally balanced. I'm not sure if the c-4 was ''original'' to the mustang on the previous engine, but it was a 66' 289 V8, with 'that' transmission behind it, and had no problems...he just wanted a bigger engine in his car.-----------one question though...can I still use a 28oz. flexplate with my setup??? I am assuming I can. Thankyou so much for the help with all this!----raimond

 

You need a neutral balance flex plate. No weight! Zero ounces. The straight six engine has a crankshaft that is balanced by itself, without the addition of external weights. The V8 crankshaft needs an external weight, since there is not enough room inside the engine for the weight.


I hope the message will get through to you eventually...ZERO weight flexplate. I'll say it a few more times, if needed.

The flexplate weight needs to match what the ENGINE needs.

 

Okay....zero balance flexplate....thankyou-----got it all covered now....appreciate the help.