'75 GMC HEI...can i use with my truck?

[72CampSpecial]

I picked up a HEI out of a '75 GMC w/350 v8 for $30 bucks (wires cap, everything)... hoping that i can use in in my '72 CampCust, Stock 350 w/ recently rebuilt Q-Jet

the more i read the more im concerend that its not a "pull the old out and drop in the HEI"...

what do i need to check/validate before i go ripping the old system out? Curve, srpins, weights, etc... are all unknown to me (in the current distributor and the HEI)

I have the HEI, the original red power source wire, the wire that went from the HEI to the side of the engine block (do i need that for mine? i done have anywhere to hook it up)

Can i drop it in, set the new plugs to .045, start it, time it and see how it runs?

thanks..