I'm hoping someone can clear this up for me. I'm trying to figure out which bellhousing I need for a TKO500 to bolt up to a roller 302. I would prefer to use a toploader bellhousing (with 157 tooth 50oz flywheel). According to Keisler, for a TKO500 with a 1-1/16" 10-spline 7.21" input shaft (6.5" input optional) I can use a regular toploader bellhousing: Keisler TKO500 But, according to Texas Mustang's TKO500 with 1-1/16" 10-spline input shaft, I need to use the Ford M-6392-R58 bellhousing: Texas Mustang TKO500 Is the Ford M-6392-R58 bell the same as the toploader bell? I understand that the TKO500 can come with different input shafts, what input shaft length do I need to have in order to use a Toploader bellousing?
I think I found the answer to my second question... "They also come in standard length of 7.250" or the short length which is 6.5". The length is determined by the depth of the bell housing. The small block Fords all used the deep 6.9" bell which requires the 7.250" input shaft. Big block Fords had 2 different depth bell housings, a 6.5" deep and a 6.2" deep. Both of those would require the short input shaft." from AllFordMustangs.com, 4th post. But I still don't know which bell to use.
The only factory bell you can use with a Tremec is the SROD/Cobra bell. You can use the older Toploader bell, but you'll need a 1" spacer between the bell and transmission.(and these spacers, available thru many classic Mustang vendors cost over $100) Both have the same transmission to bell bolt pattern but the SROD/Cobra bell is deeper to accomodate the longer input shaft of the later transmissions. Starting with the SROD, all Ford manual transmissions used a longer input shaft. The difference on the big block inputs was in the front snout that extends into the pilot bearing/bushing. You can use an older small block transmission with a big block bell, but not the other way around, unless you use a Boss 302 pilot bushing, otherwise the front snout on a big block transmission won't reach into the pilot bushing if used with a small block bell (or a truck bell, ask me how I know this)
Gotcha. So in the end I need to get the Ford M-6392-R58 (Cobra bell) or find an SROD bell and use the 7.250" long input shaft. Thanks for your help! On a side note, is it worth switching to the 26-spline 1-1/8" input shaft?
Not unless you're going to be subjecting it repeatedly to hard drgastrip launches with slicks. The small block Toploaders has a 10 spline x 1-1/16 input and were fine behind big blocks in normal driving.
