Unless you supported the area around each guide as you did the pressing, you've probably got a boat anchor. Ditto on the pressure test, and at least get the head gasket surface milled a little to be sure it's flat. Situations with long pieces of cast iron and ham-handed methods seldom end well. Straightening a bent cast iron crankshaft is done with a big lead hammer- - - - -not a press. Why are you making guides? They're available ready-made by the hundreds.
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!