Spark plug question

Gonna replace the plugs in the ex wifes 98 rodeo 3.2 with 112K miles. Not sure how old they are but they probably need replacing. Off hand does anyone know the plug gap specs. I got some autolite double platinums and they are gapped at .045 already. Since I don't have a torque wrench or time to get one, what would be safe as far a tightening them. I figure finger tight plus another 1/8 turn.

Also, I'm pretty sure that the intake gasket is leaking with the rough idle at stops. Is that something that the average person can do or should I take it to someone to fix, and how much is a fair price for parts and labor ?

Thanks

According to my Haynes manual the spark plug gap should be .040 to .043 inch.

As for your other questions, i have no idea...

If you can do the plugs you can do the gasket.

fair price at the dealer is 350 bucks.

Cool, thanks guys. Got the plugs done. Not too much problem, except the back drivers side was a bitch.

On a side note, I did notice that when turning the vehicle off there was a hissing sound. Sort of like opening a bottle of coke but it lasted like a second or 2. Thought it was the PCV grommet leaking. Since i cleaned it and the grommet was ragged and it didn't stay in the hole tightly. Replaced that, but the hissing sound is still there. Would that be the intake gasket or something else? It was coming from the PCV area of the engine. Thanks for the help.

Here is some info on IMG replacement.

http://isuzufaq.ibctech.ca/#faq5

Not sure what the hissing noise would be when you shut it off.