Hey Nick....sorry I missed your post.
You can run an 8.5:1 engine on E85.....but it will be most advantageous to have a higer CR....Somthing like 11.5-13:1.
Nice thing is that you can run a wider LSA like 112-114 to build more cylinder pressure with a "smaller" cam and still reap the benefits.
If youre looking mainly at AutoX....what RPM's do they usually run?
I take it that five speed has a deep first gear coupled with a performance oriented rear gear like 3.23-3.73's.
With regards to cams....I think youll like the cam you have...its small enough to get you good cylinder pressures and vacuum signal...should be pretty responsive with the cubes.
SWT racing is right....For the money you can spend, a holley can/will perform just as well as a BG/QFT/Proform carb.
I ALWAYS use the nylon bowl screw washers...Theyre gold compared to those piece of crap paper leak-a-ma-jigs.
Also...I always spray my gaskets with white lithium before I install them so that they seal well and dont tear when you remove them.
My personal recommendation would be a 600 holley DP with stainless high flow needle and seats....center hung floats....High flow metering blocks and gasoline style jets. Alcohol jets would be very large and probably flow more fuel than you could use. The stainless needle and seats will take more pressure too before they flood.
The carbs without the airhorn...ya know, the cool looking contoured ones...dont really offer any power advantage over a carb WITH a choke horn until you get into alot of RPM or horsepower.
I know that buick products dont like to rev....I dunno bout Rover's.
I would think that you would want a wider powerband though at more liveable rpms for the street...if you plan to drive it to the tracks.
All in all I think youre sweating the details too much unless its a purpose built race car....13:1 on E85 would be great....but gas is cheaper(sorta), easier, and more available.
You can always convert later....and mill youre heads to get a higher CR and better quench....even angle milled...although youd have to do the intake to match.
Alot of the speed will be in the chassis and the recovery power off of corners....which it doesnt sound like youll have any problems with.
Good luck and keep us updated.
God bless
-Shred