I am in the process of restoring a 1952 Chevy 3100, with a 235 (1955) engine and SM-318 3speed on the tree manual transmission. Also, before I purchased it, it had been converted to a open driveline. I am now considering my options to keep the 3 spd or convert to a T5 WC style transmission to get a better "cruising" highway speed, plus the advantages of moving to the floor and eliminating the linkages. One alternative option I am now considering is a ring and pinion change on the rear end which gives me almost the same as the OD on a T5. (T5 final gear is .63, while a change from 4.11 to 3.55 using a Patrick's ring and pinion kit would give ~ .86). I realize this change will not give the low end torque, but if the truck is not for hauling or towing, could this be a better solution than a transmission change? Any negative points to consider? Also, since my driveline has changed, what is the best way to understand if the rear differential is still an original 4.11:1? Does anyone have a visual picture or drawing of the SM-318 transmission?
Since your truck has been converted to open driveline, I'll assume the old rearend is long gone and a later one is in there now. Patrick's conversion is for the original rearend so I'm thinking that option is out. Firstly, I'd see what ratio is in there now. Here's how to find out: Jack the rear of the truck so that both wheels are off the ground, be safe - use jackstands. Put the tranny in neutral. Mark the driveshaft and a tire with chalk or masking tape. Rotate the tire 20 times while counting how many times the driveshaft turns. Divide the driveshaft rotations by 10 (i.e. if it turns 41 times, you've got a 4:11) Note: if it's a posi both wheels will turn forward, same procedure, just rotate the tire 10 times, and divide by 10. The T5 is a great choice for these trucks, and you don't need a WC box. I'm using one that came out of an S-10 p.u. You get a good range of gearing, plus the OD.
Thanks, I will give it a check. Did you convert from a 318 to the T5 and floor shifter? Do you have pictures of the conversion? Did you require an adaptor plate from Buffalo or the like to mate the T5 to the 235?
Good advice from Waldo53 regarding determining your present gear ratio first. That said, you are not necessarily bound to a T5 with a .68 OD ratio. There are numersous gearsets used in T5's, depending on original application, and first gear ratios vary considerably as well. check out http://www.britishv8.org/Artickes/Borg-Warner-T5-ID-Tags.htm Also, search Flat Ernie's posts here on the HAMB.......he is a T5 guru You should be able to bolt a T5 to your existing truck bellhousing (assuming it's the original).....with a probable clutch disc change for the input shaft spline difference. Ray
Yes, they'll bolt up to the Chev truck bellhousing. There are a few other mods necessary as well. Go to stovebolt.com and look in the Tech Tips, (top of each page) there are some step-by-step how-to's with pics there.
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