now it won't start!

First time poster here, so please bear with me...I own a '97 k1500 5.7l vortec. Blew lower intake gasket at #2 cylinder, took me 1 1/2 days to replace but did the job myself and hopefully saved a bundle. However, now it wont start. It turns over, attempts to catch, but won't start. I am afraid the gear on the bottom of the distributor was turned while it was out and now my timing is off. I haven't checked timing on a vehicle in about 15 years so forgive the simple question, but how do I tell if it's my timing causing the poor-starting? thanks in advance for any help...
Chris

did u have the distributor out. I assume you did, pull it out again and put the #1 plug at tdc compression. There will be a mark on the crank. Then put your dist in with the rotor pointing to #1. The computer can compensate enough so it should run if your timing is off a little. The u need a scantool to set the cam retard to 0. The gear at the bottom just hooks to the oil pump and that can be turned with a long flat screwdriver to line it up to the distr. Hope it helps.

You forgot the most important thing that mark on the blancer wheel will not show you tdc of compression . You could be 180 deg out. You should pull number 1 plug and tap the ign key to just crank the engine a tiny bit with your finger covering number 1 spark plug hole. Keep doing this untill you feel good compression then start looking fro that blancer timing mark