What is the length of the flexplate bolts for a C6 flexplate to a 400 crank?
The bolts are 7/16-20 x ?.

Is there a shim between the flexplate & bolt heads?

 

don't have a length for you but about 3/4" for sure. i have never had a shim on flexplate. only reason to shim flex plate to crank is starter gear engagement alignment. sometimes to much clearance between torque converter and flex plate and have to shim or add a extra washer between converter to flexplate. If to much clearance between converter to flex plate like 1/4", need about 1/16 for thrust and keep converter pump on flats of converter shaft. if you pull converter to far forward you only have minimal engagement of oil pump in tranny and could round off end of convert at flats. things to consider if interesting installation issue pops up.

 

Thanks,
I'm reinstalling my C6 flexplate. I had a TCI conversion kit installed, because I wanted to use a 700R4 OD trans. The trans worked fine, but I chewed up 5 starter drives. The adapter plate in the Krappe TCI conversion kit was not thick enough to support the starter, so I took it out. I'm going to use an E4OD with a Bauman controller. I have an E4OD with a Bauman in my '83 F100 behind a carbed 302. It's just a beater truck, but it shifts like a drag car. I'm anxious to get that kind of shifting behind my EFI 434.

The flexplate bolts from the kit are too long for the C6 flexplate, and I don't know what I did with the original bolts.

 

I think that I found the bolts. They were in a bucket burried about 3 layers deep on my workbench. I think that I have too many projects. Anyway they are 7/16-20 x 3/4", and have a sort of castelated head. There were 6 of them. Now all I need is an E4OD transmission. I'm looking for a core to use for a rebuild. I ought to post on the 429/460 forum.

 

the 700 what is the gear ratio at 1st? Believe the ford tranny is like 2.84 or 2.76. been awhile since i researched. I have a low gear kit in my c-6 and really like. manual shift valve body kinda harsh at 2nd to 3rd good to go other wise in my application. currently doing a 400 ford zf 5 speed conversion and pretty much finish. another ford guy doing the same and we are both on the similar pages on the correct path to making it work. not to expensive and pretty much anyone can do. catch you later.

 

The 700R4 has a 3:1 first gear ratio. Also in OD the ratio is about 0.7:1. It has a wider ratio than any othe Ford or GM trans.

 

3/4" if you count the base of the bolt; if not, the threaded part only is about 1/2".

I just went outside and shot a picture for you since mine is apart:



Edit...duh...nevermind...those are torque coverter to flexplate bolts...

Gimme one minute...I'll go check what you are actually asking for, LOL.

 

If we are being precise...11/16" is the length:

 

Using the depth gauge on my dial caliper, I get about 0.8" from under the head to the end. I think that there was a shim under the bolts on the head side.
What is important is that they don't bottom out.

Another problem is the block alignment dowels. I had to grind 1/8" off one of those dowels for the GM trans. The dowels are 1/2" diameter x 1" long. I have to find a source for one of those.

 

No shim on any 390, 429 or 460 I've taken apart or worked on.

 

I'll check the depth of the bolt holes in the crank, and subtract the thickness of the flexplate to see if those bolts will bottom out.

 

I got a 0.500" diameter x 1.5" long dowel from Fastenal. I went to a local machine shop looking for a 0.500" x 1.00"' dowel. He didn't have one. I showed him the Fastenal dowel and he took it and cut it down no charge. It's now installed into the block, and it sticks out the same as the other.

I checked the depth of the flexplate holes in the crank. They checked out at about 1.0" deep.

I have 5 7/16-20 x 1 1/4" set screws, and I screwed them into 5 of the 6 flexplate holes in the crank. I did this to align the flexplate when I install it. I'll put a bolt into the 6th hole to hold it in place while I remove the set screws one at a time and install the other bolts. I ran one set screw all the way into the hole, and had about 0.30" sticking out. That means the threaded portion of the hole is about 0.95" deep. Since the flexplate is 1/8" thick, a 0.8" long bolt will penetrate the hola about 0.675". So the bolt length is a non-issue.

 

thanks and considered the 700 tranny conversion but zf seems a little simplier but i was wrong. once figured out will post on here what i've done for the next ford guy.