WP pulley diffrences?

[dondb]

I'm installing PS and the crank pulley and WP pulley were so close i couldn't install the PS belt. The WP pulley I removed was 7 1/8" across, so I purchased a 6 1/4" across pulley. The bolt pattern was different...1 1/2" between bolts on one I removed and 1 1/4" on one I bought. Needless to say the mechanical 4 blade fan and spacer do not fit on the new pulley. I believe the set up I pulled off was not original to the 307 engine due to the crank pulley being smaller then the WP pulley and the one I purchased to be correct. So my question is what fan and spacer should I buy and were?? Oh yea... the fan is 18"

Thanks for any help and suggestions

[MySons68C20]

A picture would help alot.....trying to visualize your particular problem is tough without it.

[gmc684x4]

I can pull off the fan and pulley of my 91 later today and compare it to my 69 pulley for bolt pattern spacing

I am going to use the 91 serpentine setup on my 72 when I get the motor built and keep the original setup in my 69
I just finished shoving in the 91 into the shop last night to start tear down runs great bent frame got it as a parts truck

Looking forward to driving my 69 this week

I have swapped the clutch style fan into my truck in the past and pulled it out and put in my moms ford when her clutch fan failed and went back to my old 4 blade fan
both the short pumps I have on hand have dual bolt patterns drilled

I always guessed small block chev where almost all the same bolt pattern

[dondb]

I'll post a picture a little later when i can get into my shop.

And I think that's what I'm going to do....drill new holes in the pulley to match up the spacer and fan blades? The center part will keep everything centered to drill the holes so there's no wobble??

Thanks for the response Should be a few days longer before i get the truck on the road minus the bed which is getting new wood.

[Myself]

On the v-belt smallblock setups there is a short water pump style, then an early long style, and a later long style too.

[dondb]

[dondb]

On the bottom picture the 2 pulleys have different bolt patterns via distance. The one closest to the fan blade is 1 1/2" along with the fan blade and extension piece. The one to the right is the new one from speedway and the bolt distance is 1 1/4". So top picture i took the extension piece and made marks to size and drilled new holes at 1 1/2" to fit the existing extension and fan blade. Interesting is the WP had bolt hole patterns for 1 1/2" and 1 1/4".

Anyway it's on and now I need a new belt.....snowball effect