Toploader

A common problem with most owners of BOSS 302s is that they don't know what type of Toploader 4 speed transmission (trans) they have. Whether it's a code 5 - Wide ratio or a code 6 - Close ratio. We can only guess based on what we see with the registry. It appears to us that most 3.50 rear ratio cars got the Wide ratio trans because the higher rear gear needs the lower 1st gear to be able to pull out better. Most 3.91 cars got the Close ratio, for what we believe to be a good road race set-up, for less RPM drop. Most 4.30 cars got the Wide ratio for obvious drag race qualities. This is only our opinion of what FORD seemed to be doing. We may be wrong. If you want to know what type trans you have for sure, here are some tips:

Trans out of car and apart - 1) Remove lid of trans, if the input gear is smaller than the input bearing, it is a Wide ratio. If they are the same size, it is a Close. 2) Remove the bearing retainer. If it has a grove on the input shaft it is a Wide, if not, then it is a Close. 3) Put the trans in first gear. While turning the input shaft, count the number of turns it takes to complete one turn of the output shaft. If it takes approximately 2 3/4 input shaft turns then the trans is a Wide ratio (2.78:1). If it takes approximately 2 1/3 input shaft turns then the trans is a Close ratio (2.32:1).

In Car - Jack rear wheels off ground, run engine to normal operating temperature. Put trans in first gear and let idle steadily, write down speed. Put trans in 4th gear and let idle steadily, write down speed. Divide 4th gear speed by 1st gear speed. This equals ratio.

Another method is just about the same except drive car out on a flat road and again record the idle speeds in 1st and 4th gears and divide. A tach can also be used by picking an exact rpm.

2:78 is a Wide ratio and 2:32 is a Close ratio.

In Car or out of car - Look for a small metal tag attached to the transmission. On the tag you should find one of the following codes:

1969 - RUG-E3 = Wide ratio

1969 - RUG-AG = Close ratio

1970 - RUG-AV = Wide ratio

1970 - RUG-AW = Close ratio