I dropped a 1972 or 73 360 into my 65 Valiant. The Valiant was an original V8 car. I reused the 904 tranny and stock converter from the Valiant.It is cable shifted. When we tried to fire it up,the part of the starter with the teeth that engage the fly wheel would not engage. Upon further inspection it appears the starter bearing or bushing is hitting the flex plate. The flex plate is a balanced one that I had used in a 727 at one time. Thinking that maybe a 904 needed a different flex plate I called Summit racing to see if they stocked them and if there was a difference. They told me they are the same for both trannies.Now I'm scratching my head and asking you guys what you think the problem might be and what my next step should be. Oh yeah,we also changed starters to make sure that wasn't the problem.

yes you need a 904 flex plate & unless you internally balanced the 360 when you built it then it is externally balanced & you need the B&M special flex plate. Go to Summitt/jegs etc & lookup the B&M flexplate for "externally balanced 360/904 with internally balanced torque converter". I've used it in several of those swaps. OT the 273 logs are EXTEREMLY restrictive & reportedly the magnum ex manifolds will fit & the 92/early 93 ones have a 2&1/8 outlet and the later ones have a 1&7/8 outlet & the external dimentions of both groups are the same. The BEST manifold setup is an early mag on the dr side and a 340 HP pass iron manifold on the pass side. Then there's headers if you want to mess with them, Hooker 5208 fenderwells and Harolds under chassis ones might be being reproduced. Inquire on www.forabodiesonly.com and www.slantsix.org and www.bigblockdart.com for more info & might scan eBay. EDIT I've seen (pics of) that flex plate for both that Summitt is referring to but they're mistaken on the app & it ain't the right one for your swap. MORE EDIT The one you need is a B&M 10239. Look for a used one as it'd be cheaper for you and it is a non wearing part & they are around on occaision

One other thing, since you will be taking it apart.

Did you know that the snout on the early torque converter is smaller than the later ones? This means the 30 you have needs an annular ring pressed into the crank register so that the T/C snout has something to center upon.

Are you using a mini starter (late model)

I ran into that with the b&m 904/727 for a 360

need the 360/904 only

I swapped the starter for the old style and didn't need to change the flex plate

RapidRobert,Thanks for the correct part number and the good info. I knew I could count on moparts! I am using the old style starter

what is the difference between a 360 B&M for a 904/727 and one just for a 360 B&M for just the 904?
the flexplate with the big bite out of it is 360 and the small bite would be cast crank 340?Do those differences apply to 727/904 cast crank 340?

The difference is the diameter, the 727 flexplate is larger in diameter and will cause the starter interference experienced by the OP.

Even though the bolt circle is the same, the 904 has a 122 tooth ring gear and the 727 has 130.

..Thought i had this sorted out but will have to check my parts.
I have an external balance flexplate for a cast crank 340 and i will be using a 904 transmission.
thanks for the info.

just checked and i will need a 340 cast crank 904 flexplate but don't see one listed in Summit unless TCI 102350 would work.
maybe i will have to weld the appropriate weights on my 904 converter.

You'll find that the pilot hub on the '65 converter is 1.550" and the register in the 360 crank is 1.810". The spacer ring is available from a couple of sources.

---

Should I look for this spacer ring at Summit or would I have better luck with a transmission shop/builder?

Yes decades ago Wildcat auto had em for $20 to your door. You might inquire at one or more of the 3 sites I posted & likely someone there can properly direct you to a current source