I have this 87 blazer that is  TBI 350 that i just picked up the timing is set rite on the money but it seams gutless and it has 180 lbs of compression in all clyinders vacuum is at 20 to me it seems like way to much compression for this truck could the timeing chain have jumped  

Nope, if the timing chain had jumped you woudl see a drop in compression, plus it would run like crap and be pumping black smoke out the tailpipe.

The TBI 350 in 87/88 was only rated at 190 horsepower. Combine that witht he heavy drivetrain of the Blazer, and you're not gonna see snap-your-neck performance.

That being said, there are several things you can do to get more horses out of your blazer. The first is to get a intake and TBI unit from a '92-'95 full size. These years featured a bigger TBI unit with more flow capability. All the sensors and plugs from your '87 will bolt right up.

The next thign you could do with pulling the heads of is a cam and valvetrain upgrade. Install a bigger cam, better pushrods, valvesprings, and rockers, and you'll see a nice performance gain. I converted my '92 Silverado to a hydraulic roller cam and saw a big increase.