I have been carefully removing excess weight from my all original rust free and excellent running cotswold blue '72 XJ-6. I used to be into Porsche 911s only but i have fallen hard for these beautiful Brit saloons. And the kids like the leg room..
I started with removing sprung weight: the 1/2 ton spare tire, jack and tool kit. I then removed the head rests and reinforcment plates below the aluminum thresholds, all of the 1" thick sound deadening material except at the fire wall, all of the air conditioning equipment under the hood, the hood insulation and more, sprung: the steel wheels were replaced with later XJ kent alloys finished in solid bright silver without the black spoke detail. This saved 6.5 lbs per wheel w/o wheel centers. The exhaust was modified I removed the final mufflers for straight pipes and i lost weight there as well. I am running only the rear right fuel tank removing the other working tank and feul pump, I have relocated the battery to the spare tire well. I have done more but don't want to be a bore.. The interior looks stock and original. It has made a noticeable performance difference. I am carefully saving everything on the racks. I am planning a manual trans conversion, does anyone know how heavy the BW12 in these cars is. It works very well for its age but seems like a HP sucker and looks very heavy being cast iron, i'm looking forward to feeling the difference when complete. I may go with a vintage 4 speed w o.d. but being cast iron w/ the o.d. unit they seem like they'd be heavy also, so a modern 5 speed box like a BW T5 which weighs 75 pounds may be the ticket. Any info re trans swap and weight/performance is appreciated. Thanks