i have a 1999 monte carlo with the 3100 and i blew a head gasket so i pulld the heads off and sent them out got them back yeaterday and put them back on and put everything back togeather and when i whent to start it, it backfired and it just cranks relly slow..so i pulled the pulgs and checked for compression and it has none at all..so i pilled the valve covers off to make sure the rockers where still workin corectly and they all are in workin order...i checked the push rods and they are all in the right places...if any one has any input on this matter that would be wonderfull!
thanks..

 

How did you install the rocker arms? Are the push rods back in the same place. The exhaust push rods and intake push rods are different lengths. If install in the wrong place it will bend valves.

 

yeah i put them all back in the same place they came out of..the ex rods are longer than the in rods..everything is where its suposed to be...ive done these 3100 probly 10 times and this is the first one ive had a problem with one..i got the heads back of and they ollk fine all the valves look good there is no signs on the pistons of a valve makein contact..