Crankshaft pulley

[sreta]

Hi guys ! Does anyone know the diameter of crankshaft pulley for olds 403 in T/A ? I found different data online, 8-1/8, 7-7/8... Mine engine came from 98 regency('78) and the pulley is a little bit more than 7-3/4(198mm). So I was wondering which one is the right one ?!

[Wallington]

Got one in a box here, standard 4-row with smog and A/C. There were a few used. 4-row? 3-row? Overall diameter? Any codes or stamping on it? Also depends if yours had AC or Smog, or retains that setup still or won't match.

[sreta]

198mm overall diameter, 3 row with ac, no smog

[Wallington]

possibly #412235 pulley KS.

[sreta]

Yes, I guess that's the one I have. It's 7-7/8, which is 0.1" bigger than mine. I got mine zinc plated and it looks like crap. Beside rust pitting, 2nd and 3rd row are separated and internally can't be flushed from acid properly, so it starts to rust immediately after plating. Now what I have found, there is a version of this pulley without split rows, which probably doesn't have rust issues. I almost bought one from ebay, but someone was faster than me. Maybe that's the 8-1/8 inches pulley, maybe it's year related, maybe someone knows...

[sreta]

Mine pulley with split rows on top, vs non split version. They also look different on the inside.

[Wallington]

The part number and/or code is stamped into the faces, no need to guess what they are. You still have to have a matching combination of pulleys that work with each other and your options, which I don't know.

Since I have nothing to do I dug through my boxes but I only have a Californian set left from 77-79 350/403. These are A/C and Smog pump. Useless for what you want to know but I'd gone that far I may as well take some pics and measurements. I'd already sold my non-AC pulley and the rest were earlier year Olds.

This is a KK water pump pulley and K crank pulley. They are essentially the same height even though they don't mount the same way, just for pics.

Oldsmobile 350 403 KK water pump K crank pulley AC Smog (2) by Ben, on Flickr

Oldsmobile 350 403 KK water pump K crank pulley AC Smog (1) by Ben, on Flickr

Oldsmobile 350 403 KK water pump K crank pulley AC Smog (3) by Ben, on Flickr

K Crank pulley diameter over 3 belts

Oldsmobile 403 K crank pulley diameters (1) by Ben, on Flickr

K crank pulley diameter over A/C belt

Oldsmobile 403 K crank pulley diameters (2) by Ben, on Flickr

K crank pulley height measured to mounting face - yes, there's the thickness of the mount to add for overall, I stuffed up.

Oldsmobile 403 K crank pulley height from inside mounting face (1) by Ben, on Flickr

Oldsmobile 403 K crank pulley height from inside mounting face (2) by Ben, on Flickr

KK water pump pulley diameter

Oldsmobile 403 KK water pump pulley diameter by Ben, on Flickr

KK water pump pulley mounting face height.

Oldsmobile 403 KK water pump pulley mounting face height (1) by Ben, on Flickr

Oldsmobile 403 KK water pump pulley mounting face height (2) by Ben, on Flickr

[sreta]

 I took some measurements today. No numbers or letters on crank pulley. The diameter is let's say 7-7/8(-2mm). It's let's say 2-1/4 deep(-2mm). The water pump pulley is KE, the same as yours, 5-5/8 wide, 3-3/4 deep. Both stock, came originally with the engine. Maybe they put 8-1/8 crank pulley in 79, it's still enigma for me. As I said, I almost bought this wider pulley, as the seller said it was removed from '79 T/A.

https://thepartguy.com/pulleys.html