I would pull the valve cover to be sure he's not lying. Make sure its not a rod knock.

 

it started sputtering and misfiring the other day It barely wanted to start. idled rough. it smoothed out when I floored it buy it's real nasty at lower rpm. no codes it's not the opti or the o2 sensors. it's been n the shop but they went havin any luck. so i went and got a 99z28 this weekend. stock 6 speed. the performance is willin to take my LT in exhange for 3k of work on the LS.

 

there you go, much easier to get that kind of hp from a ls. so wheres the pictures???

 

here's the 99z 6 speed i picked up this weekend.
i need a lil in put on my 94z. its sputtering and ruining like **** at lower rpms. it doesnt idle at the 900-1100 range like it should it wants to drop to below 500. but when i get it above 2000rpms it fine. i was just sittin at a stp light when it started doin this. ive changed the plugs and checked the wires. the opti didnt get wet.

 

scan for codes and restart the computer. unhook both battery cables from battery and touch together for 10 or 20 minutes and reconnect to battery. no ses light

 

that didn't work. How would I know if the opti spark went out while I was drivin? cuz after I tried the battery thing I took it down the street. I floored it for a sec. it got up in speed pretty good got it to about 90 then it back fired a few times the died and now it won't start at all.

 

see if this helps 4th Gen LT1 F-body Tech Articles