motor swap questions

[mortimer]

What exactly do you look for in an engine? I see generator and snowblower replacements but what exactly is the difference? I see 3 with the same torque specs from Briggs and about $100 difference. The torque specs are a bit confusing and I have learned quickly to see what older models they replace.
And the clutch sleeves, I looked up one and it says "Excess crankshaft will need to be trimmed off and may also require drilling and tapping original crankshaft hole deeper." Is that meaning you don't offset the new engine? No way am I cutting a crank on a new engine.