New to Big Blocks

Update... Everything fits and I have 0.090" between the two pulleys (probably the same as before)

By my measurements the crank to water pump CL to CL is 6.8" - 6.81"

1/2 the diameter of the WP pulley 6.875/2=3.4375
1/2 the diameter of the crank pulley 6.5625/2=3.28125
distance between the 2 pulleys 0.090"

3.4375+3.28125+.090=6.80875 ~6.8"-6.81"


6.8 is more likely then 6.81 and 6.75 might be even more likely but as accurately as I can measure 6.8 looks to be the number.

(for the pulley measurements I had to use a tape measure (I don't have a caliper big enough) but the measurement between the too was measured with a caliper. I should have measured in several pulley position combinations but I got lazy)

(There is a person selling a water pump pulley that he says measures 6.5" and his tape measurement shows that. My concern is the WP bolts are very close to the pulley I found a 5.75" pulley in the wrecking yard with the correct back spacing but it hits the bolt heads) I did some playdough testing and there is not a lot of space between the inner edge of the 6.875" pulley and the heads of the bolts BUT the 6.5 MIGHT fit I just don't want to risk the cash.)