Hey guys, Are the C4 transmission's from 250 6 cyl the same as the C4's from the 302? I need my tranny rebuilt and have an extra one from 6 cyl car, was going to rebuild it if it's the same.
the 250 c4 uses the same bell housing as the 302 but the trans from the factory probably wasnt built to handle the same amount of power. but in your case if your getting it rebuilt anyway it shouldnt be an issue. all the other smaller I6's have a smaller bell housing pattern. you'll also need a diffrent fly wheel to mate it to a 302
i've used numerous 6 cylinder c-4's. have had them rebuilt before using and never had a problem. if it has the small bellhousing you need a 157 tooth flexplate and small engine plate. if it is the larger bellhousing you need the 164 tooth flexplate. whichever one you have you can swap them out as the bellhousing just bolts on to the rest of the tranny. i prefer the smaller one as it gives you a little more room for the headers.
You can do a search on this topic as it has been discussed many times before. The 6 cyl tranny will not have as many clutches as the V-8 version. It is easy to add the clutches during a rebuild.
The things to watch for are: is your 302 stock? is the front servo one of these; "C", "H", "A", "R" Was the six cylinder a 240, 250 or 300 cu" engine? does your car weight less than 3500 pounds? If you can answer yes to all of those questions then you will be alright using the C4 behind your 302 if: you install a cooler in addition to the radiator cooler change ATF at 24000 mile or two year periods (which ever comes first) don't race it at all you drive like you have a weak transmission These are general statements and there are always going to be exceptions. Most of the C4's behind the 240, 250 and 300 cu" engines have 5 clutches in the forward pack and 4 clutches in the direct clutches. The intermediate servos are the big weak point and if it has one of the smaller servos (not those listed) then you may have a problem with rapid band wear unless you install a 47-2 TransGo shift kit. Even then it is possible that the intermediate band will slip under load. That causes heat and wear. Both contaminate the oil and can cause problems. There are servos that you can buy to replace the smaller one in the transmission. The transmission shop may have one of the four listed as used but good parts. Ask if they are willing to sell you one for the rebuild. With the proper servo it is as good as any factory C4. Paul
