I'm certainly no blower expert although I did research a lot of different scenarios before building my 354 Hemi with a 6-71.
First you have to decide what you want to accomplish. Do you want Saturday boulevard cruiser that makes noise, idles at 1200 rpm and generally isn't usable for a daily driver? Or do you want a vehicle with tons of low end grunt, decent fuel economy yet with enough HP to smoke a lot of your former friends... you have to decide that first.
Blown engines can be very docile and content in everyday traffic. A good cam along with the proper boost can give you the best of both worlds... tire shredding torque and reasonable economy... 15 to 17 MPG hwy numbers are not unheard of...
And they do not have to be expensive if you shop around, use eBay and attend some swap meets. I paid $20.00 for my core 6-71... took it off a 70's vintage Dodge truck. Rick Dean did the gas conversion for $285.00 plus parts... total was around $450.00. I bought a BBC drive kit with a new front cover from Dyer's Blower Service on an eBay auction for under $300.00.
I found a NOS Cragar intake at an old hot rod shop in Massachusetts... had been laying under the bench since the 50's... $225.00 plus the ride. Bought a couple vintage Cragar pop-off valves from former top fuel driver Darrell Gwinn.
All in I have under $1200.00 in my blower...ready to run.
I had George at Clay Smith Cams grind the cam to specs he and I agreed upon. He had me install it 4 degrees retarded to calm down the idle and give it more grunt and better economy. I have an 850 Edelbrock sitting on top the blower plate.
I put my big $$$ in Venolia pistons... they cost me $650.00 custom made to my deck height and desired compression ration (8-1)... stock replacements would have only been a few hundred dollars less. Venolia even called my machinist to verify the combustion CC's on my cam request... great service IMHO.
If you plan on running a good performing daily driver you can get away with cast pistons and crank... I have seen dozens of these over the years, in both SBC and BBC, give good reliable service. If you plan on pegging the tach to 7k on a regular basis you will need better parts.
You'll also need a good break-in oil when you reassemble that engine... and use the BEST oil you can find when you finally finish it. At a recent oil seminar I attended, the guy doing the event told me the oil company he works for found the engine that would give their oil the ultimate work-out was a BBC at 8500 rpm. If the oil kept that engine alive it would keep anything together...
Blown engines are fun... but your right foot will determine how much that fun will cost.
Last edited by Mojo56; 05-25-2012 at 12:09 PM.