motor swap - new cam - unsure about pushrods

[gripp]

This seems like the place to post, so here goes. The Ford dealership recommended asking where I bought the cam (Summit), and I can't seem to get the guys from Summit to hit me back.

Here are some details about what we're working with:
car: 1982 mustang GT
302 machined to 306ci from 1980 Ford pick-up
using cylinder heads from the stang - bone stock
edelbrock perf.rpm hydraulic flat-tap cam .496 & .520
stamped rockers
stock F302 crank
stock pushrods are 7.875 inches from ball tip to ball tip.

I'm guessing the new rods should be a hair shorter? I'd sure like to have a good fit, but there's too many sizes to choose from!?!? I thought about using an old radio antennae to get the length, but that's probably laughable. Does anyone here know someone with the same set-up? (probably not since I'm using those worn-out cylinder heads).

Anyway..What's the best method for determining absolute push-rod length? I know there's a sweet-spot, but I'm not sure how to measure down there. Maybe one of yall will lend some help?

I also lost my "dowel pin" for the cam. I had a spare that I passed over to a friend. I can't find the part in stock at the Ford dealerships and they want $25 bucks for it!? Where could I find one of those boogers? Mine is lost forever in the garage somewhere.