SM465 and 420 trans question.

[redneckmafia01]

On these transmission. Did they make more than one gearing ratio? I thought that all the 420s are the same gearing. No matter what year.

[J.C.]

465 was a 6.xx ratio, 420 was a 7.01? i think?

[7387chevynut]

Both of those manuals, came with only 1 available 1st  gear ratio.........didnt matter if truck was 2wd or 4wd, it was the same.

The SM465..............1968-1991 had only  1st gear ratio. 6.54

The SM420 .........1947-1967.......had only one 1st gear ratio, 7.06

The SM420 is the better of the 2, but is very hard to find compared to the more common SM465.

[redneckmafia01]

That's what I thought. Just making sure.  A guy tried to tell me they made different ratios in the 420 tranny. Thanks for clearing that up guys.

[shortbed78k10]

Is the sm465 still a good trans Or is it junk?

[7387chevynut]

Is the sm465 still a good trans Or is it junk?

its a great stick trans, very common and very popular with GM truck gear jammers.

[shortbed78k10]

i love the creeper gear its so deep

[michigan maniac]

my 1/2 ton chevy with a sm465 would pull 3/4 ton and one ton trucks backwards!!!

[redneckmafia01]

My 80 3/4 ton with a 465 pulled everything i needed it to. I always bent the shift forks in them though.