MaroonMonsterLS1

Clean out your lines. Use kerosene and flush the lines both directions. Then blow them out with air. Low line pressure can cause the clutches to engage somewhat but still "slip" some and thus burn the clutches out too quick. Also, use a z-pac for the 3-4 clutches, much better than stock rebuild frictions and not much more expensive, just for some insurance...Also, is it the same trans rebuilt 4 times or 4 different transmissions, meaning different cases and valve bodies etc?

HexenLord

Is it really that hard to swap an 80e into an F-body?

I picked up my transmission, flexplate /w spacer and bolts, and a Transgo HD2 for $600.

Your setup doesn't look to be wild enough to need an extremely expensive converter. Revmax makes good 4L80 converters for $500 in your stall range.

Add in cooler line fitting and adapt whatever cooler you may have now. You'll be in $1500 when its all said and done. If it wasn't for the converter, I would be in a lot less than that. I sold my TH400 and converter and recouped 100% of the cost of the 4L80 swap, minus the converter. There are tons of people putting 700+ whp through stock 4L80s with a transgo and they seem to live forever.