what kind of torque can you get with all the bolt ons and cam?

Here's the deal. The Slant is a torqueless wonder. Very small bore with a huge stroke and way too long of a rod.
It isn't until around 3 grand that the speed of the rod swinging past TDC begins to match the speed of the pressure wave and things start to come into sync.
If you want torque, go find a 170 block and rods and then grind away at a 198 crank till it fits. You'll give up 25 cubes, but more than make up for it in angularity.
If you're sticking with the 225, put a clutch behind it and use an RV type cam.
Lots of bowl work, but dont increase the size of the ports or valves..you need all the velocity you can get.
And, squeeze. Like was said before, compression builds torque.
Good luck!