There's a firewall modification that makes a lot of sense to me. Buy a small steel tub wheelbarrow (they're cheap!) and trim the tub down to fit the center of the firewall and provide a smooth, well-fitting dimple for distributor and bellhousing clearance. It gives you a lot more leeway about fore/aft positioning of the engine and trans, without seriously compromising foot room in the cab.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!