Big Block Perches

[66_C20]

I’m working on getting some fitment issues worked out with cramming a 454 into my 66 C20. I have the motor itself bolted in using the original motor mounts and perches that were in the truck and everything seems to fit pretty well, had to massage the firewall a little for the valve covers but I expected that. The main issue and big hurdle I have right now is gettin the headers to fit. I have a set of Doug’s shorty headers with a 3/8” flange and 1 and 3/4” primaries and they just aren’t fitting inside the frame rails very well. I expected to maybe need to trim a little of the top of the frame rail but even that wouldn’t get it done. Then I came across these big block motor mount perches from classic parts and the motor mounts they suggest using with the perches and was wanting your opinions on whether it might be worth it to spend the coin on them.

https://www.classicparts.com/1963-72...nfo/79%2D065/#

I’d gladly spend the money on them if it’ll fix the issue but I’d hate to shell out the cash for it to make no difference on header fitment. The only other idea I have is to move the motor up and forward but I don’t want to run into clearance issues with the radiator/fan and water pump pulley. So any and all help is welcomed and appreciated.