Point me in the right direction

Converting from a nitrous setup to a blown alcohol big block. I've got a setup I'm trying to round up parts for. It will be a 4.620bore and 4.250 stroke tall deck with a set of dart pro1 20° heads. This will be an aluminum rod motor. I have an 8-71 littlefield high-helix delta opening stripped blower with a bird catcher. Would it be possible for that blower to make 20# of boost? Or will that engine size be too much for that? Should I drop the bore size to a 4.560? I'm not against having to sleeve the block to achieve the bore size. My goal for this little blower will be 1500-1600hp. Has anyone ran these heads? What would be a good starting point for the port nozzles and hat nozzles? Also will be on M5

 

Anyone?

 

I have a new dart steel pro race block for sale

 

I would definitely drop the bore size. You don't need to build monster cubic inches to get in that power range. I worked at Eagle racing engines (they built Scotty cannons stuff) in the late 90's and we built a 540, steel block with dart 360 heads that made over 1900 with a 14-71. So I would say with today's tech you shouldn't have a problem with 1500

 

x2 on the bore sixe. You will have a real problem o-ringing between the cylinders. Or even the MLS gaskets are iffy with that little material. With a 4.5" bore you can lay 2- O-rings side by side with plenty of material.

Corey

 

Jody, how much and details?? sean

 

Brand new dart pro race block. 10.200 deck, spread pan rails. +.600 cam, .904 lifter bores. 4.500 bore ( may need finish machine work ) cam bearings and freeze plugs still in box. Took it on trade from a friend for a set of heads I wasn't using. No rust, always stored in a plastic bag. List price is over 3000.00 , sell for 2500.00 plus the ride. Thanks

 

Thanks guys. I will look into the smaller bore size for sure.

 

I run a cast iron dart Big M 4.60 bore, 4.0 crank 532 Dart 360 heads with an 8-71 HH. Individual o-rings in the block deck, nothing done to the head surface. Solid copper gaskets. Makes 28-31# of boost at 46% over. Been running it for 3 years with this setup, no problems. I agree though, if I was starting from scratch, I would go 4.50 bore, but the 4.60 bore is what I had and it works for me.