Hi John , 
   Thanks for the reply . I'm just knocking ideas around in my mind for now and thought I'd get some more advice from the pro's . I'm still gathering information and I'm trying to figure which would be the best way to go .  How much would you expect to to pay for a good gas engine ? Also , would the radiator have to be swapped out too ? And do the 3-speed bellhousings bolt to all these engines with no adapters ? Bottom line , if I went this route is the engine all that I need ? Other than cutting my hood up for the exhaust and breather and flushing the fuel tank . 
    On a different subject , do all 1755's have a belt driven hyd. oil pump in the front to the oil cooler  or was that an option ? I don't have one on mine . Thanks for you time , I used my tractor for mulching ( ? ) my overgrown pasture with a 7' bushhog a couple weeks ago and the engine didn't self destruct . The oil pressure dropped to about 20 psi and stayed there at around 1800 - 2000 rpm . If it lasts through one more sickle mowing and raking ( I think it will ) I'll get it fixed instead of getting the engine UNLESS it turns out I can swap cheaper . Thanks again , Randy-IA