Give Scott Koffel a call. He has been building those motors for a long time. They run stock low deck blocks at that power level. I think they use aluminum main caps and a tall fill to make them last.

Your long term goals point to the RB block. So if that is your plan, go RB. The other option is an Indy Max low deck aluminum block.

But IMO, a 511 CID low deck (4.25" stroke x 4.375" bore) will make the power goal. Aluminum main caps (can be made to 440 main size like mine is), and some block filler will minimize risk if the cylinder walls are thick enough. I had to sonic check a few blocks to be happy, and I am just over 700 hp (not B1 heads).

Randy: I am leaning to a 400 block with short fill, aluminum caps,440 source girdle, line bored, bored to 4.375, 440 source 4.25 crank with 2.20 rod end, Aluminum rods, Ross 14-1 pistons, Comp .690 roller, bush all lifters holes in block. B-1s with max port. This 511 should make 1,000 h.p with maybe alittle more after tuning. Better have a great trans, driveshaft, rearend, and axles. Birdtracker+

RB blocks a must for 4.5 stroke engine, and good length rods..I have seen no real evidence that a B block is strong than a RB.. Just claims..I have seen them both fail. And seen/heard of plenty of low deck motors splitting the cylinders too. And cap walk is no better between the two

About 4-yrs ago I was in your same place, Randy. The only thing that changed my course of action was the fact that the '72 lowdeck block I had revealed a slight crack that was in an area when it could've been fixed by drilling a hole at the end of it, but I opted not to put an expensive rotating assembly inside it only to probably have it all blown out the bottom or my B1 heads ruined from breakage. So I went from doing a stock blocked 496 to my alum. 540.

In the end for what I was planning to do with the car the Keith Black lowdeck aluminum block was basically a must. Completely setup for nitrous, it made over 900HP N/A and adding two big guns on top of it, the stock block was not going to live long at all.

But for what you're attempting to do the stock block will be okay in N/A form and you won't have to go overkill on parts to use, especially in a fairly light car. Get it as light as you can. My 25.5 '72 Dart was a tank. Ran a best of 9.16/149 at 3480#'s "on motor" with me in the seat. The car had the AlterKion frontend and ladderbar rearend, Glide and 4.10 gears, M/T ET Street's 30x13.5 DOT's.

Anyway, hope some of this info/pics help ya. Thats Chuck Millen of Best Machine Racing Engines with my motor he built back in '05. I flew to Michigan for the dyno session. If you can find the Sept. '05 issue of Mopar Muscle there is a complete article on it.

I don't get on the internet much anymore due to time, so if you want to chat or need info, feel free to contact me via PM's. Good luck and take care.

Wes

Here's another pic of the motor with Vince Impasato at his dyno shop.

With the two GUN's

The '72 Dart

nm

Well my only B1 experience is with low deck "baby" motors. My first was a 451" in the stone age in a tube chassis Daytona. It went 9.0's at 149 all out using a out of the box heads, stock block and crank at 2650lbs. My next one was a 511 low deck that I had in my 67 Valiant 10.5 car. I never ran it on the bottle but it went 9.0's at 3470lbs with a set of fully ported B1's, stock filled block, aluminum caps, and an Ohio 4.25" crank. Neither of those were dynoed but made pretty good power and were pretty basic parts. The motor that is now in the Cuda is 4.50" bore 4.125 stroke low deck in at 525". It has been dynoed and makes right at 1050hp with a set of B1MC's, Callies crank, and KB block.

In the end I think you can make 850hp pretty easily. Wont take any exotic parts to get there or huge compression ratio's. My 451 was about 13 to 1, the Valiant was 13.5 to 1 and my current engine is 15 to 1. I think the stock block stuff will live fine if you keep the bobweight light and do not have any detonation issues. The caps and girdle will help and IMO the block fill will as well.

Randy, you will be better off to do it right the first time. Get the block first, so your foundation is right. Then you have the basics in place. With times like they are, good deals will surface. Follow up on for sale web sights like racing junk, etc. Wes is great at it, may have a good list of places to check.

I ran stock Rb blocks for years ,with B1 port heads from koffel ,after about 150 runs that will crack in the mains of the block, and that was with all kinds of main caps, get a good block mega or what ever,