Oh, ok, I'll play devil's advocate here. The engine is a grenade and every time you hit the gas the pin slips out a little further, this is a given. If you've never driven anything with one of these monster engines in it before - it's a whole lotta fun before the boom.
I worked at a small shop that had built a single cab that had one of these engines in it complete with a transmission that could take the abuse. One day when we were nearly done with the project the shop owner asked me if I wanted to drive it around the block. He said "if you want to have some fun, put it in first, rev it to about 3 grand and sidestep the clutch". If you've never seen the back end of a single cab hop off the ground it's an interesting sight to behold.
After that, I took it around the block to make sure it was running ok - it was. It had just rained and the roads were a bit slick, I was going about 25 or 30 in 3rd gear and tapped the gas. As the back end started to swing around the only thought going through my head was "don't hit the telephone pole, don't hit the telephone pole". Fortunately, I managed to keep it on the road and after a bit of recovery time I immediately turned around and drove back to the shop.
So if you want to have a bit of fun for a short while, get the engine. If you don't, and there are several very valid reasons not to that have already been stated, then hang onto the ASBug for a bit longer.