I'm looking for a crank pulley part number

[Bob R.]

I'm looking for a correct crank pulley for my 63. The 63 AIM calls out part number 3766987 but in searches on eBay I find that number and I find 3858533 noted for the same use. What is the difference in these two parts and are they interchangeable.
Thanks for any help identifying the parts.

[Joe L.]

Re: I'm looking for a crank pulley part number

I'm looking for a correct crank pulley for my 63. The 63 AIM calls out part number 3766987 but in searches on eBay I find that number and I find 3858533 noted for the same use. What is the difference in these two parts and are they interchangeable.
Thanks for any help identifying the parts.

Bob------

GM #3766987 was the original crank pulley used for 1963 Corvettes with 340/360 HP engines. It is a 2 deep groove pulley and of 6-3/4" OD. It was discontinued from SERVICE in August, 1964 and replaced by the GM #3858533. This is a very similar pulley except it is 6-5/8" OD.

The 3858533 will definitely SERVICE the 1963 applications originally using the 3766987. However, there is no way that any 1963 Corvette could have originally had installed the 3858533 as it was not even "born" during that model year.

[Bob R.]

Re: I'm looking for a crank pulley part number

Thank you Joe

[Joe L.]

Re: I'm looking for a crank pulley part number

Thank you Joe

Bob-----

By the way, the 3766987 was also used for 1964 and, possibly, very early 1965 L-76, L-79, and L-84. The 3858533 was used for most or all 1965 L-76, L-79, and L-84. Thereafter, it was used for all except C-60 1966-68 L-79, 1969-73 L-46, LT-1, L-82, and most 1974-79 small block.