If you're not going to have the engine over 4000 rpm, I wouldn't worry about anything. And if you're going to run it on Propane, I HIGHLY recommend hardened seats, as I have a 320 V8 Packard that was used as an irrigation engine on propane and one of the exhaust valves was 1/2" down into the port!the plumber said:I have experience turbocharging my 292 straight 6 in my work truck and would like to duplicate my approach to a rebuilt Packard 288 I have found. There are no 9 bearing units around here. I will fab the exhaust manifold as a tuned length purge welded 304 ss tubular unit divided for the split scroll t-03 turbo (or t-04, I will get advice on that). The split scroll and small diameter tube header develop boost at very low rpm. I will fab up an aluminum intake for two ipsco 225 propane carbs in a blow through set up. The 288 and my 292 are both develop gobs of torque at low rpm. The same approach should work, with more vintage looking fab work this time. Boost will be limited to 8-10 psi. My questions are crank whip related. The 288 will be in a smallish 50's English car with an automatic and used as a cruiser. I don't race or do burnouts. I doubt that the 288 would ever see 4000rpm. I know turbos are easy on the bottom end but am I safe? Is there a better harmonic balancer available or can I adapt one? Do I use custom light weight pistons and aluminum rods (this works on high rpm 292's)? Also, I need to install hardened seats is there plenty of meat in the block for that (I assume so)? Are there larger S.S. valves available for the 288? How much would you guess a 288 weighs without the manifolds? I would appreciate anything else you can recommend not mentioned here. I hope I am not killing your with my questions. Thank you Mr Turbopackman.