Mercury Cougar Owners banner

1 - 12 of 12 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter #1
Hello

I am going to drop a well built 351c / TCI street fighter C6 into my 67. Does anyone else have this setup? My concern is clearance using that transmission.

I was running the 351c with a 4 speed prior to this setup.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #3
I am worried about clearance between the top of the trans and the car, also I am unsure I can use my current cross member.
 

·
Registered
Joined
·
2,518 Posts
You will need a c-6 crossmember, but it will fit. The big block cars had them. The main thing I would be worried about would be headers. Are you running 2v or 4v heads?
 

·
Registered
Joined
·
19 Posts
Discussion Starter #5 (Edited)
I got the C6 cross member from autokrafters, but it is a very different style. My old cross member is a rectangular style shown below and my new one looks more triangular also shown below. As for headers, I am running 2v heads, with a valve job and porting.

Headers = Hooker Headers 6913HKR

old cross member current cross member.jpg

New Cross Member c6 crossmember.JPG
 

·
Registered
Joined
·
2,518 Posts
You are on the right track, those are the correct parts. Those are also the same headers I have and they worked fine with the C-6. Now, do you have a drive shaft for it?
 

·
Registered
Joined
·
5,883 Posts
Yeah, you'll need a driveshaft cut to length and balanced.
But, the C6 shouldn't have any issues with clearances in the 67/68 unibody.

However, mock it up and install it just to be sure. You can do this relatively easily with an empty C6 case. Get a junker, pull the front pump and valve body, then shake the guts out of it and *voila!* lightweight mock up trans case. Bolts to the bellhousing and your mount, lets you see what's up before you get the real one in there, and is easier to wrestle around even if you're using a lift. Costs maybe 25 bucks for a cracked case core or a junkyard part is a bit more, but not much. Not much demand for the c6 nowadays in the used parts biz.
 

·
Premium Member
Joined
·
2,142 Posts
I did find clearance problems using the "ribbed" C6 case and had to switch to the smooth case C6. Other than that it was a drop-in (for 1970).

The new triangular support is correct. I have both the "C6" and "FMX" and they both work just fine. Not sure what the fuss is all about.

Driveshaft is 3" shorter than FMX/C4 length but any d/s shop can fix you up with one.

Headers fit fine. I use Ford Powertrain.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #9
I got a guy that will mod my drive shaft and balance it.

Thank you for all your posts.

I can now finish welding in my floor and modifying the cross member attachment points with great confidence.
 

·
Registered
Joined
·
5,279 Posts
C6 crossmember is made to clear the vacuum modulator
 

·
Registered
Joined
·
152 Posts
Hey buddy I know this is an old post but I've installed the 351C with a C-6 in my 67 and it fits great. Compared to the 289 I feel its easier to access the headers and spark plugs. Used factory motor mounts and C-6 crossmember and it all bolted right in. Hope yours is a success too
 
1 - 12 of 12 Posts
Top