With a blower, cylinder heads are not as important, since you are FORCING the air in anyway. Granted big ports would definitely help.
If it were a desicion of rebuilding old heads or buy Eboks....I buy NEW! It's not worth the money to rebuild old heads with ss valves and springs and seats....... For just over $1000 you could have a really nice set of new heads that would be dern near a bolt on. I would surely do a check on the new heads before installing them, but at least they have all new parts. Production stuff tends to be a bit off on tolerances sometimes.
Well the 6-71 was brand new in the box from GMC. It was a gift from a friend that bought two at an auction. The end bells on both were cracked from being dropped, but you don't use those anyway.
The intake is a Blue Thunder version with the 3" spacer on top of it. It makes running a stock dist. possible(which I did). The rest of the drive is BDS stuff.
You can pretty much mix and match the pieces as long as the drive is for your particular engine. It is the length of the snout that makes it line up with the crank pulley.
With my connections, I had about $1700 in it. That did not include two Holleys. That is about HALF what the whole kit costs from BDS. Friends/sponsors are a good thing!
Anyhow, with the stock blower I needed to shorten the front shafts to make it run on a gasser. Real diesel blowers are gearbox driven(double set up front to speed them up). You can't have all that stuff, so you cut the shafts, re-thread the ends and bolt the back gears on it. You install the BDS spline hub on the one gear and install the drive cover. For the back cover I bought the nice BDS version with cast rips and is thinner than the factory model. Alot of people just make a flat aluminum cover, but this is nicer looking.
Anyhow, it works flawless, 3 yrs running. I have it set for about 6 lbs of boost. The motor is pretty stock yet, with a mild cam. I want to build a good "blower" motor(ie: forged pistons, good rods, blower cam) someday when the money is available. For now, it runs good, looks good.
I looked at trying to install this on my '69. The only real problem is the blower sits back far enough that I think it will interfere with cowl/firewall area. You know how it the top area sticks out into engine compartment, this will be major problem with blower and carbs sticking up there. I'm sure there would be ways around this, but I just did not take it any farther.