Give me a little schooling in 12 valves. What are or are there differences in the 12 valve engines from 93 to 98?

I had a '03 HO that I sold last August and am ready to start looking for it's replacement. Figured I would try either a 1st or 2nd generation. I owned a '94 back in '94 and enjoyed the truck but just don't really remember it as there has been about 20 vehicle since then.

I know '91s (mid) back were not intercooled and would like to stay with an intercooled truck. Was it just the body change in '94 or were there engine differences?

Thanks

 

94-95 auto is 160hp, 94-95man is 175hp, 96-98 auto is 180hp 96-98 man is 215hp. They all have the p7100 pump but they are different sizes I wish i would have known that before i got mine.

 

As you saw Manuals > Autos in the horsepower department. The 215 Pump also has a "new" plunger design that has a notch cut into the top of the plunger instead of the surface being flat all the way across. 96-98 manuals are the ones you want, they are the "best" IMHO.

 

I do want an auto. So the 1st generations had a mechanical pump and all 94-98 had electronic pumps?

 

No, 94-98 has a mechanical p-pump. **edit** make that early 98, late 98 went to the electronic pump.

 

In 97, they started using the hydroboost brakes. Before that, it was vacuum assist. If I were looking for a 12v truck, I'd look for a 97 or 98 model.

 

Any 2nd gen 12v is good and they're all practically the same. The stock hp ratings don't mean anything because with a couple mild mods all the trucks will run pretty much the same (not comparing trannies here). Don't pass up a good 94-96 just cause it doesn't have hydroboost brakes. Extended cab models started in 1995. There was major changes to body and engine between 1993 and 1994. All "2nd gen" 12v's are 94+ and are intercooled. A full medium-duty engine in a light duty pickup that blew all others away at the time. And still does...