Well I have had a strange vibration in my Charger since building the 512 low deck, at about 2k & 3500, sometimes worse & other times just a little, been reading some post on hear about some Harmonic damper issues
, Dwayne from Porter Heads mentioned about one that the bolts on the engine kept getting loose & the damper was replaced & all the loosening bolts stopped,I dont know what brand that one was, SO, I bought a Power bond SFI damper, its like a different car now, smooth as can be, VERY happy, Thanks guys for the input on Moparts !!!!
Charlie

1968 Charger COLD A/C Hilborn EFI
512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim
2020 T/A 392 Stock 11.79 @ 114.5