how fast do yo think a stock mta4 would go on road

and how much horsepower has the .28 got

About 36-38. And i belive its around 3 hp.

It's actually 2.3 claimed HP...I wouldn't go off of claimed HP, though (here are some reasons why). The stock .28 is pretty decent, better than you'd expect. It's also easy to tune and maintain. With a good tune, it pushes the MGT pretty darn good...

ya when your picking an engine dont go by Hp.

go by they way its built and rpms