I changed my intake gasket, and now wont start!

sounds very much like a very simple vacuam leak ck all vacuam hoses to see if all are connected also not broken or cracked if all is ok replace base gasket on throttle body.these are the least expensive and simplest to ck.After checking all these with no succese while eng is running take wd-40 and spray along where intake manifold and heads meet could be intake manifold gasket leak.if this dosent help or cure problem take to a qualified tech you will save money in the long run.

Have u checked the cadeletic converter. It can do funny things

No it is not. Sounds like a leaking intake gasket which most chevy's are notorious for. Thankfully companies like Fel-pro make a "problem solver" gasket, which will elimate the chances for the leak agin.

it will need to be properly diagnosed,it can be a gasket,hose,spout,welch plug,drain plug etc etc.best bet is to get the cooling system pressure tested,this will pin point the leak.

Your timing is off. Did you have the distributor out when you changed gaskets or maybe took the plug wires off?

Change the distributor cap and rotor.

Change modulator valve on transmission.

check the intake gaskets. in the middle front and middle rear. If they are oily, it more than likely sucked part of the gasket in. When it warms up the leak gets bigger. The easy way to check is to get some carb cleaner and spray all around the intake while idling and warm. DO NOT SPRAY ANY EXHAUST PARTS , carb cleaner is combustible. The truck should stumble or even shut off when spraying with the carb cleaner if there is a leak.

If you had to loosen the engine mounts and raise or lift the engine to gain clearance you may have accidentally pulled apart an electrical connector or cracked the distributor cap when it hit the firewall. good luck

If it does there may be a recall on it. Always check with the dealer before doing a big repair. Even though the truck is old they may still do it for free.