Depends on the cam. If the original design, had say .100 deep heat treatment, I don't think reducing the base circle, .050, means you only have .050 left of heat treating. People regrind cams all the time. It works. But only if, the cam CAN be reground. A good cam company, can determine that, before taking your money. They don't Re-heat treat the cam after a regrind. From my small bit of research I did on this topic a while back, the heat will warp the cam. Thats why they heat treat if first, then grind the cam straight during manufacturing a core/lobe.

Tim has the AFR 8002 spring upgrade. That spring, is a PAC # 1940. This spring, is PAC's entry level spring, at a cost of around 200 dollars a set. It is in their "hot rod" series of springs. Probably a decent spring, but just because it carries the name "PAC", doesn't mean much. Isky makes a full Tool Room spring, that costs in the 450-500 dollar range. Certainly not the same quality of spring, that Tim has. Nor is it meant to be, or marketed , as an "endurance" spring. Pac does make endurance springs, that cost much more than that spring, just as isky/psi, make springs that cost 150 bucks a set, or 450 bucks a set.

Hot Rod Series Springs are designed to offer the engine builder and hot rod enthusiast a mild upgrade and replacement for their hot rod.

241* Lobe, 680 lift, basic valvespring, 250 hours, seems like alot to ask. Merc engines went that long, but they also had easy cam lobes, most in the 590-630 lift range, and didn't exceed 5200rpm.

i only use babbit bearings. I will never use a roller cam bearing. Even the drag race guys seem to be getting away from them. I use a coated bearing made by Durabond.

The addition of the 55mm and .904 is beneficial on any engine really. It's certainly not needed on something with a small to moderate cam, but it sure can't hurt. The only downside to it is cost, not that it's really that much. The acceleration rate is slowed, the contact area is larger, spreading out the load over a larger area. The wheel and axle are larger, making them stronger. Also, when opening the lifter bores to .904, you can correct the geometry. I don't care which block you use, none of the lifter bores will be perfectly perpendicular to the cam. They are pretty close in both the Merlin and Dart blocks and in 99.9% of the applications, you would never know or have an issue. The GM Bow tie block is another story. I've seen where those had to have bushings installed instead of steel on steel since boring to .904 would not clean it up. The bores were off so bad that just cutting to .904 would not allow the cutter to touch everywhere. We had to open them even more and install bronze bushings in order to correct them and run a .904. Again, you would more than likely never have an issue due to lifters bores being off slightly. However, if you are boring them out to run .904 lifters anyway, you would be a complete fool to not correct them. The valve train is by far the weakest link on a BBC, so anything you can do to help it out is a step in the right direction.
Eddie

to be honest mid 70's would make me happy with this hull, I had 420's boat was fun... but knew 70 ish the hull came alive for running rougher waters and still not totally taking out drives (running it right helps) then I had the chance to buy a boat that had them 565's making 600 hp, knew I could buy it and sell of the rst, keep power and make money still... so I did, then that got a little messed up with some issues they had that I fixed, like was fun running 73 all the time, then 2 seasons later I toss a rod, then find Bob, he promises me 700HP spinning existing props to 6000 puts me at 78-80 mph, far stretch but numbers say so, I figured it would do 75-76, daily, then the rest is history... that being said....
I love my boat, a gun may be in future but still no speed demon, its paid for, I could take a ,loan and go buy a TS if I wanted a payment, I pick and chose money things in life, mostly pay cash for toys and most things I have, so this is what I can afford without stretching, if money is there I spend it, if not I lay low and don't do much like last winter..so I left it. Here we are now, it needs addressed so I will address it, I don't really want to go broke and reinvent the wheel, but will change a few things and get better results, and reliability of not touching them I hope for a bit, speeds? well anything over 73 will make me happy, if I was that concerned about all out speed I would have not gotten a Mistress or maybe not even a Cig, I love what I have and old boats in general, one reason being even at 75-80 in a Mistress is doing well, and in the $$ area I can afford to play with while living life, family, other toys and so on... Kinda like Joe, I wanna keep playing with it to gain speeds here and there, to learn, and say wo that slug ran what?? this mess is not my fault so I must just fix it... when done we see what it does, if I decide I want more boost will be next, but that's also not the best thing on TRS, so who knows what future holds, with friends having cancer and things like that I literally live one day at a time, you never know guys....I deal with the NOW not what ifs or laters...

MMB's 38 is coming up for sale. Just sayin'...

Hold up what? The yellow one?

Yes, he has the yellow one. Blower motors and konrad drives. He has marine kinetics cams, but he says they are working great in his. I wanna say there are 540s with 420 blowers, intercoolers, etc.

Was gonna look into that gun no power on eBay but since I have to rebuild upper half of my engines because Bob sucks I can't buy it... Thx Bob Madara!

Heres a thread I had started about tims combo, in another forum. If anyones interested.

http://www.speedtalk.com/forum/viewt...hp?f=1&t=47746

Yes sir.