The "Chevy" starter motor for 153-tooth flywheels is a direct fit to Buick big-block V-8, and--I think--some if not all Buick small-blocks, maybe even V-6s. The "Chevy" starter motor for 168-tooth flywheels has a different mounting system--the bolts are offset instead of "straight across", so those don't work on Buicks. My photos are of the 168-tooth version, but the info applies to the Chevy 153-tooth and Buick application also. Finally ready to upgrade my ol' Chevy engine to a new-style Delco Permanent-magnet , Gear reduction (PG) starter motor, replacing an original 10-MT old-style starter. There are several versions of the PG-style motors, including brand-new aftermarket items most of which come from China. (I bought a rebuilt Genuine GM starter motor.) Remy issued a Technical Service Bulletin in February 2016 regarding the replacement of old 10-MT starters with the new, smaller PG-260 "mini starter" like mine. http://www.remyautoparts.com/The-Latest/2016/February/Remy-Starter-Upgrade-10MT-(SD300)-to-PG-(PG260) One of the things in the service bulletin is that all PG-style starter motors are machined for a 10.1 mm knurl on the starter bolt. This is a larger knurl than the old starters and engines used, which was about 9.7mm (about 3/8"). Therefore, to PROPERLY install a PG-style starter on an older engine block, you need starter bolts with a stepped knurl--the knurl by the threads which fits into the block is the same size as the older starter bolt knurl. The knurl closer to the bolt head, that fits inside the starter housing, is larger. ARP does NOT list a correct bolt for this application in their catalog. The ARP 430-3514 "Mini Starter" bolts have a standard non-stepped knurl. They may be correctly sized to go into the engine block, but a PG-style starter will wiggle around on the smaller knurl. The ARP bolts may be correct for other aftermarket mini-starters, but not the PG-series. GM p/n for the "long" 9/16 hex head, 3/8-16 thread bolts is as shown above in the photos, 12338064. The p/n for the "short" 9/16 hex head, 3/8-16 thread bolt is 14037733. A Chevy 153-tooth and Buick starter would take one long and one short bolt.
Jamie from Start-n-Charge has been selling these for years with what I believe are the correct bolts. The challenge you run into is if you want the 2 smaller lugs on the starter relay to keep your wiring as it should be. Jamie's has the 2 lugs and finding an application with 2 lugs was TOUGH (I could not fine one for automotive). Mercury Marine actually uses a version of the starter with 2 lugs on the relay but while they are PRICY, you can find just the replacement Mercruiser relay for around $30 (as I recall). That said these small body starters are a DREAM to install VS the big heavy originals and they spin the engine over better as well.
Looks like I've been lucky so far. I put a mini starter on my truck. It started hard when hot for as long as my FIL owned it. Replacing that starter helped, but it looks like I need some new (correct) bolts and to recheck the gear spacing. Thanks for the good info!
The solenoid with the extra, "R" terminal for points-style ignitions is available. Most of these were made for vehicles with electronic or distributorless ignitions, so the solenoid doesn't have the "R" terminal. If you look in the Remy link, you'll see that they list part numbers for the starters that have the extra little stud on the solenoid. A person could either buy that starter, or use that number as a cross-reference. These starters have an 11-tooth pinion gear. The old 10-MT pinion was 7 tooth for everything except Olds Diesel. Even if the new starter didn't spin as fast, the gear ratio is different so the engine would spin as fast or faster. I don't have mine installed yet...another couple of days so the weather can get above freezing would be nice. I can hardly wait to see how this all works out. Remember, these bolts are for the Delco-Remy PG-style mini-starter, and I suppose the aftermarket clones of the PG. I don't think they're needed for other types of aftermarket mini starters.
