Bore size combos for Dart Sportsman block?

[Mus408]

Thinking on spending the bucks for a Dart based 351 stroker.
What other bore combos with 4 inch stroke. Was thinking of 4.155?
Don't want to take it to the max,but possibly something larger than the 4.125 bore size.
A nice torque happy 550 HP for my street project,is what I'm after!

[bobcowan]

4.125 x 4.000 is the starting point with the Iron Eagle and Sportsman blocks. That give you a displacement of about 427 cubes.

4.185 x 4.250 is maximum recommended by Dart. 468 cubes. 4.185 pistons will probably have to be custom made. 4.250 stroke will limit your rpm's a little bit.

www.dartheads.com

[Mark O'Neal]

Strokes are 3.850 - 4.000 - 4.100 - 4.170 - 4.250

I don't see the point in boring a $2,300.00 new block.

[blykins]

I did one with a Dart block at 4.155" x 4.100". It was 445 ci and made 586hp @ 6000 on the first full dyno pull.

No reason to not go with a larger stroke though. A 4.25" stroke gets you up in the 450-460ci range depending on the bore.

[quickjack]

4.000" stroke x 4.125" bore = 427 ci

4.000" stroke x 4.155" bore = 433 ci

4.100" stroke x 4.125" bore = 438 ci

4.100" stroke x 4.155" bore = 445 ci

etc, etc... it all depends on what you want to do/spend.
It won't be difficult to hit your 550 HP goal if you have a combination that's happy together.

[Bob In Ct]

I should never read threads like this one. I've been quite happy with my Ford Motorsports Windsor for 10 years now but all of a sudden I'm getting the urge to replace it with a Roush Stroker.

Bob