Dont know if I'd do it again...
I put an SM465 in my 72 K5 I had years ago,after its TH350 made me late for work too many times waiting for it to shift into forward gears every morning..
It was a week of 6pm to midnight non stop work,between stripping the parts out of the truck I bought for the SM465,and installing them--had to change the tranny,transfer case,and yank out the power brake booster(which was full of brake fluid and was junk too!
),to put in the clutch pedals--then cut out the floor hump for the shifter,and install the manual tranny flywheel,bell housing,etc..luckily the driveshafts fit!.
.I put a brand new 12" clutch in it--it lasted 1 week before one of the 3 levers broke on the pressure plate--changed it again when the second one did the same thing a month later!
--finally put a diaphram type pressure plate in and had no more clutch problems--then the splined "coupler" between the tranny and transfer case started rattling--found out the splines on the tranny output shaft were pretty worn--put 2 new couplers in it in 25,000 miles,and even though I filled it with RTV and Locktite,it rattled nearly every one of those miles and drove me nuts!..
I like manual trannys--but I did not realize the SM465 was more suited for a dump truck than a K5--I had 3.08 gears,since it used to be an automatic,and it was horrible with the SM465--I didn't like the way second gear was really "first"(the LOW or first gear was only good for creeping or taking 0ff on steep hils,or wall climbing!)--the jump from second to third was too far away--you'd wind it out in second,get it up to 25mph or so,then it would bauugghhgg in third gear--and you didnt need 4th gear until you hit 65 mph or so,or it would lug!...might have been a lot better with lower gears--but I hated it after I put the SM465 in it--now I had to shift it all day too in city traffic!..I like an automatic much better--until they start croaking,then I wish it was a manual again!..
I would have liked it much better if GM had a tranny with better gear ratios and easier faster shifting,like the M22 Muncie tranny they used in camaros and GTO's and what not--I thought the "3 on the tree" three speeds had a better overall ratio spread and were faster shifting than the clunky SM465 ever was--but they had none of the strength of the SM465's.(and no "granny low" for crawling)..so I guess its a toss up...I feel they still haven't made a "good" manual tranny yet--one that has good spacing betwwen gears,is an overdive in top gear,or is rugged enough,all in one box yet..I was almost tempted to get one of those 5 or 6 speed Richmond Gear tranny's for it..but I sold it instead..
Not trying to discourage anyone,but I regretted putting the SM465 in my truck--between all the work,then the clutch problems and couplers being a PITA,I was wishing I just had the TH350 rebuilt and kept on driving it--cost me about 500 bucks for all the parts,and a ton of labor...I didnt use the truck off road much,so most of it for me was a waste of time and money..
I think I'd BUY another truck with a manual tranny already in iit before I go thru all that again!..
