I am running a slightly modified 351C in my 71 Pantera, mechanical roller cam, Holley 750cfm double pumper, Boss 351 intake, 10.25 to 1 CR and GTS exhaust system. I am still running the stock distributor with stock advance but have added an MDS6A box to it. I initially set the timing for around 14 degrees BTDC. I noticed a slight knock if the engine was pulling (up a hill at low revs). I turned the timing back a bit (around 10 degrees BTDC) to stop the pinging. When I did this I checked the mechanical advance and it seemed to be still advancing above 4000rpm with the vacuum advance disabled. I have stopped the pinging but now the engine runs hotter and it doesn't have the explosive acceleration that it had before. I am wondering if it would be worth while to toss the stock distributor and put in one of those MSD distributors (PN8477) that come with the adjustable mechanical advance so that I could recover some of the performance. What do you think? Thanks.
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