Hey y'all I posted awhile back about this consistent low rpm stutter I was having with my 92. About a month ago it got really bad to where the car was missing and sputtering so bad I couldn't really drive it. Anyway did some digging and found all passenger plug wires were arching all over the place. Several had been worn through from rubbing on stuff. I'm thinking someone changed plugs a long time ago and didn't route the wires right. All the little wire looms were broken off or missing. So fast forward to this week. Replaced plugs and wires. Opti is unknown. Looked pretty crusty so definitely older. Car runs pretty good now. The low stumble is gone for the most part. Idle is still kind of rough, definitely hunts a little and lumpy. Sounds like it has a small cam lol. I'm thinking that is a vac leak somewhere I haven't found. The new real problem which I'm confused on is when I'm driving. When I'm driving at 50+ in OD if I put a load on it the car shakes very violently. It's like a horrific misfire, but I don't think it is. It seems to hold at 2k and thumps hard. The only way I can describe it is a mix between a terrible misfire and hitting a rev limiter. Really bad when it tries to downshift going uphill or when trying to pass. Does not do it when in regular drive. Car also pulls very smooth under light acceleration. Also surprised myself last night when I did a full throttle pull. Pulls very strong for a 30 year old, mostly stock LT1. I'm lost what to do next. Opti? Fuel pump? Torque converter taking a dump? Worn u joints?