Blown head gasket.. i think

[bd]

Adding to the above, consistency on the compression check is important.  Be sure to 'pump' each cylinder the same number of times.

[81_Chevy]

alright bd ill do that,

on another note about that modulator; when i had the sparkplug out i cranked the engine over and fluid came out but it wasnt gas, it had a red purple tint to it just like my trans fluid... im starting to think that its a bad modulator, because what else had the purple/red tint to it? just trans fluid.. man if it turns out to be the modulator going bad again im gunna feel pretty dumb lol. and since i just replaced it about 4 months ago i havent even bothered to check it. 

[81_Chevy]

well it turns out that it was the modulator that was bad! 

when i adjusted it a while back i must have adjusted it to far and ripped the diaphram, i pulled it out and it wouldn't hold a vacuum. luckily i still had the old modulator that turned out it wasnt bad in the first place! i tested it and sure enough it held a vacuum! i put it in took it down the road VERY minimal smoke coming out and then i just didnt smoke anymore! its still backfiring a little but that prob just because the plug is dirty, ill pick up a new one tomorrow. other than that she runs great! im so glad me and my dad didnt have to pull the engine apart i wasnt looking forward to that!    im just glad to have "The Beast" back on the road! thanks for EVERYBODY's help! another great reason i absolutely love this forum!

Truck on,
-Nic