I do get passed a lot running the car with modern cars.
The motor I just built will probably be about 10-12hp more and I am toying with building up a full 1300cc motor with 38/33 valves. That motor would be around 95hp at the wheels.
The extra 20hp is enough that I'd be faster than 3/4 of the cars in that run group.
So that's around 160hp and that engine is around 340lbs from memory. The motor would add about 145-150Lbs to the car. I think those would have has a Type 9 transmission behind them and that would add another 40lbs over a 56 series trans.
So I'd expect this would be about 200-225lbs heavier than the standard Ute.
Dave I've tried driving the 1200 in the same manner that I would one of my single seat cars on slicks (read what and tidy) and it ends up going about 2 seconds a lap slower.