OK
I am about to become your "go to" guy.
That's because I have a small fleet of Ford six powered race cars and hot rods.
My avatar car (blue altered) runs a built 300 with a crossflow six - runs 9.0s @ 147 in Super Pro.
My Logghe altered (orange car) is run at vintage / nostalgia races a few times a year. It weighs almost 1800# with me in it (225#) and runs low-to-mid tens. It has run 9.7 in the past but I slowed it down to above 9.99 sec so I don't have to jump through the chassis cert hoops any more for the car since it only gets raced three or four times a year.
But the most relevant car in my fleet is probably my Frenchtown Family Truckster. I built it to potentially run Super Street (10.90 index) but only bracket race it now. Here are some specs:
weight: 2150# (car and driver) w/ 70 lbs of ballast.
2.47! gears in a 9" rear. My plan was to switch to 4.56 gears for Super Street. 12" or 10.5" slicks
300 six, flat top pistons, bracket / circle track roller cam, dual quad intake w/ two tiny Autolite 2-Vs totaling
340 cfm equivalent 4V flow,
rollerized valve train, big valve ported head, stud girdle.
Powerglide 2-speed w/ 1.82 low gearset
4000 rpm stall 8" Coan converter
Even with the 2.47 rear gears and the tiny carbs it will run 11.90s on the hand brake or 11.60s on the trans brake, shifting the car at 5000 - 5500. On pump gas. I highly recommend the Powerglide over the C4. [There are valid reasons why most serious bracket race cars use Powerglides and 9" Ford rear ends, for that matter]
I recommend making the wheelbase 125" so the crushing torque of this engine does not overwhelm a too-short chassis. It can still look old-ish at 125". Also I'd use a stall speed of at least 4000 RPM. And build the chassis to cert for 9.99 and save yourself headaches in the tech line.
A 300 six with iron manifolds weighs 490# dry.
Check out the website
www.fordsix.com for great advice. Good luck with your project.