I need some help here. I am putting together a 55 and came across what appears to be a good deal on a 302. The guy is offering either a C4 or a C6 transmission for the same price (my choice). I need to know which way I should go. From my understanding the C6 is a much stronger transmission but heavier and will eat up more hp. The C4 is lighter but not as durable. I plan to use the truck as a weekend driver. I don't have any intentions of taking it to the drag strip or towing heavy loads with it. What are the advantages of going one way or the other. Also, anything I should be looking out for on the 302?

Keith

 

C4 is plenty of trans

 

The C4 is a good transmission and much lighter than a C6 I think.
Allegedly a stock C4 is good for upto 400hp anyway.
The C6 was more often found mated to the 351's whereas the C4 is more commonly found with the 302. The C4 might be easier to fit under the trans tunnel/cover (mine fits perfect - I have a '71 302 with a '78 C4).

Check which year 302 it is - pre '72 engines had better compression ratio compared to the mid 70's ones. Or later models going onto EFI etc ok (the ones in between were a bit weedy for HP). Post 1971 C4's are better.

All the info on C4's you could ever want is here:
http://www.fordmuscle.com/forums/c4-transmissions/

 

C4, .......all the way!

 

Ok, it sounds like the C4 will work fine. Thanks.

The 302 is a roller motor and has some sort of edelbrock intake and holly carb on it. The seller said that it was running when he pulled it but I haven't met someone selling an engine that hasn't said it was running when removed. The heads are pulled from the engine so I can get a good look at the cylinders to check for scoring. Of course this means I can't do a compression check. I'm not sure of the year. I have asked him to send me the serial numbers off the block. Anything else I should be looking at before purchasing it? The guy wants $300 for the engine and transmission combo. Sound reasonable? I'm a sheetmetal guy so most of the drive train stuff is new to me. Any advice is appreciated.

Keith

 

300 is a great price for the engine tranny combo. If you buy from a used parts shop the tranny alone would be 300ish

 

The C4 will be fine if you are not going to be towing regularly, carrying big loads regularly, and driving like the village idiot.

Weight is a concern, but having a C6 and noting some of the difficulties that created, I would definately think size and space would be the greater concern between the two. The C4 should fit comfortably, the C6 will take some finess.

 

$300 sounds good. Hopefully it includes post 1987 heads.

 

The c-6 is about 3 inches longer than a c-4. The trans pan is bigger than a c-4 could cause some fitment issues, nothing the blue tip wrench can't handle. The c-6 does require a bit more H.P. to turn. There were 2 different types of c-4. The pan fill usually found in F-100's the dipstick screws into the pan. And the case fill dipstick usually found in cars. The flex plates are 157 tooth and 164 tooth. the 157 is for a c-4, c-6 uses the 164. The 302 c-4 is a great combo it will work with out a hitch. Good Luck!