The C6 is quite the unit, the only thing you have to watch out for is that all C6's that came from a car behind an FE use Type F automatic transmission fluid. If you use the common dexron type fluid the life span of the transmission will be shortened AND you will lose performance. The type F fluid makes the older C6's bite harder on shifts.

Justin

 

Now there's an oldie! I haven't seen an oil filler/breather cap like that in almost 30 years

 

The manifold is off of a 64 T-bird, i really like it. makes adding oil a snap.

Justin

 

sorry, a little off topic. What happens if I screwed up and put type F in my 86 Bronco that has the C-6? It feels like it's slipping to me.

 

It's my understanding that the "F" in type F stands for friction modified. I've used it in G.M. THM350s and they seem to firm up in the shifting too. FWIW, I've seen THF (tractor hydraulic fluid) dumped into THM350s and they keep on chuggin'. I've seen it, but don't recommend it.

 

So have I screwed up my tranny or what?

 

Type F will actually make a C6 last longer. Ford started recommending dexron/mercon to ease what luxury car buyers deemed "harsh shifts".

Type F fluid won't allow the clutches to clip as much as mercon fluid, so the trans will shift harder and faster- the way it's supposed to.

Justin

 

Going back to the header issues, the 4x4 390 headers come down pretty close to the block. Do you think those would work? I have an 85 light duty f-250 that I also am going to swap a 390 into. I will also have it easy to hook up the hydraulic clutch to because I got a bell housing from an F-600 flatbed that has a slave cylinder and eveything on it already. Also do you guys think a an np208 transfer case will hold up to a 390 with a four barrel, RV cam, and possibly headers with a 8.5 comp. ratio? This truck has the tired old six in it and we use it on the farm. Plus I think it would have a fairly decent get up and go attitude. It would kind of be a sleeper. I think I'll post up a thread when I start working on it and also try to get some pictures.

 

Sad day. Truck is totaled, got stolen last saturday and the guy drove if off of the end of a T in the road. took out a 10" cedar tree, 3 6" oak trees, and came to rest on a 22" oak. Driveline is OK, but the body is shot and the frame is twizler shaped. I'm picking up an 86 now with a worn out 302 that I'm going to put my 300-6 into as i tear down the 390 to make sure nothing got broken in the wreck.

The estimated speed at impact was about 65 MPH. The cab survived remarkably well, but for how much blood was inside the truck, how bent the steering wheel is, and how big of a knee shaped dent in the dashboard there is I don't think the thief fared too well.

Back to the question at hand:

no, 4x4 headers won't work. they drop right into the crossmember. they have to wrap back like 4x2 headers, but if you run a manual the headers i tried dumped right into the clutch fork. The only headers i think would work are the sanderson short tubes for 390 powered galaxies. they fit in the same hole as the stock manifold, so they ::should:: work.

Justin

 

Well see the 85 truck is a manual trans. Justin, were you saying they hit the clutch fork you made yourself?

 

no, the 4x2 390 headers in a manual transmission 1980 and up truck with a 4 speed the headers will dump into the clutch fork no matter what, or at least if you try to use dynomax headers like I did.

That's the part that confused me, the only parts of my truck meant to go together are the motor and he trans and the trans is the only thing that kept me from putting headers on my truck.

Justin

 

Man, that sucks about your truck Hoxiii. From the way you describe the truck the guy driving it probably didn't fair too well at all. All that work just to have something like this happen. Are you going to get any money out of it? I'd say not much, but something is better than nothing.

Matt

 

nah, liability only. i'm not even reporting it. I already tracked down anoth truck for $300, so it'll work out just fine.

Justin

 

Man, sorry to hear about your truck! It would seem your beast was too much for him to handle, I guess theres some satisfaction there....

Any plans to re-use the 390?

 

I'm going to tear the 390 completely down and make sure the block isn't cracked or anything. If it's still good the motor will go back together and be installed.

I know the motor stalled instantly, so it wasn't run without oil or water which is definitely a plus.

The truck had been parked becasue the brakes had been acting goofy. first application nothing would happen, second it'd slow down, and third pump it'd lock up the rear brakes completely.

Justin