If you want to stick with your carb setup, I'd strongly recommend the B&M / Holley underbonnet blower. The latest 177 cube blower is no taller, but slightly longer than the smaller 144 cube blower.
I had a little B&M 144 blower on a 302 windsor motor in a stupid old TD Cortina of all things
The motor was nothing special (hydraulic cam, hypereutectic pistons, iron heads etc), but the low down torque was WAY more impressive than my 460 Falcon. The old Cortina could leave tyre marks down the highway just by rolling on the throttle in top gear!!!
Have a look at the dimensions here:
http://www.holley.com/HiOctn/ProdLin.../SCK/6500.html
It should hopefully fit under your standard hoodscoop. If not, you have a bit of fibreglass work to do. I guarantee that you'd be happy with the performance of these blowers
Craig