I'm in the process of replacing the rear brake flex line with a ss braid Russell line. Very frustrating day and more muscle aches - I didn't even realize I had muscle there. The only way to gain access to the fittings is to sit under the raised car between the gas tank and diff. The bottom and front of the tank needed to be degreased because the oily stuff(undercoating) was rubbing off on my coveralls. Despite having applied penetrating fluid to the line fittings for a month, using a brazing torch to heat the nuts and setting fire to the undercoating, burning through the rubber line(brake fluid burns as well), spending hours with the line wrench gently forcing the nut, tapping with a hammer, rounding off 2 of the 3 fittings, finally using the vice grips to loosen the nuts. Despite the car being oiled underneath, the brake line fitting threads were seized rusty requiring lots of time to clean. Very difficult to do without a hoist. I'm trying to keep costs to a minimum(wife is already upset I bought the car) but the proper way would have been to replace the axle brake lines and most likely the brake cylinders and who knows what else will break. 31 year old brake lines are a ********&# even if the car has not seen salt. I have exceeded my quota of swear words to 2030.