C&R heat exchanger for LSA motor in a 1969 Camaro

[BeeCee]

Fellas, feel completely useless, don’t post on here much(at all), I’m at the end of a long night working on my VA install, total pain in the ass when you don’t take the fender off haha..

Anyway, the bottom bracket is stumping me on this C&R exchanger.. I’ve searched for an explanation on the internet to no avail. How does it attach to the rad support? Only one of three holes goes through, the other two only have the hole on the front? Am I supposed to drill the other two out for access to the back? What’s the spacer for? These washers don’t even seem big enough to catch the support haha..

Any insight on this is appreciated, kinda stumped. Didn’t want to start a new thread so bumped this one.