I've always believed a 427 could only be increased to 453 ci or(454). Obviously guys are getting more cubic inches out of the 427. Just how many cubic inches can you get out of a 427? Can the new aluminum blocks or the new blocks from genesis be bored larger than the stock old iron blocks? Are sleeves being used? What about stroke? Are there aftermarket cranks other than the 428(3.98 stroke)?

 

Yes!


There are new blocks that can be bored beyond 4.25", some substantially more.

Ther are also new cranks up the 4.25" stroke.


500+ CI FEs are readily available. It just takes $$$$$.

 

Shelby blocks are advertised to take up to a 4.5" stroke. Combined with their max of 4.44 bore you get 557 cubic dollars, oops, inches. Not very realistic though. It is however becoming more common to see them in the 472-496 range, with 500+ simply being a preference. Mine has a bore of 4.375 and stroke of 4.25 for a total of 511. They accomplish this through the use of replaceable dry sleeves.

It all depends on how fast you can afford to go. Billet cranks run $2450-2750. Shelby blocks with big sleeves go for around $5900. Gotta have good rods for that much stroke,$500-1300. Custom pistons, $700-800. No flat tappet stuff when your feedin' big inches, cam $300, lifters $350, rockers $699, Ported heads $3500. These numbers are ballpark, but close. A Shelby based stroker is gonna run at least $18,500 and go up depending on options. Not that your question is about money but it is always part of the equation.

-Scouder

 

Is anybody making cranks with more than 4.25" stroke?

 

Yes. LA Enterprises, Velasco, Scat, and probably Crower all make billet cranks for the FE and you simply specify the stroke. Shelby initially suggested that I use a 4.375 stroke in mine, but I was concerned about rod length/angle so I stayed with 4.25.

-Scouder