Anyone out there have hands-on experience on the short and tall decked Dart block. I am planning on building a 427 or 434 using either a Worlds product Mowtown II or Dart block. Any recommendations or suggestions???

 

The motown is an excellent block - the dart iron eagle is probably a bit better - but you are going to have to buy mostly all "rocket" block spec accesories (oil pan, etc.) so it ends up costing a bit more. Either will be sufficient for most street buildups, etc.

 

The iron eagle has a raised cam and spread pan rails ala "rocket" block but is also more expansive because of this. You can run a regular cam AND have stroke in this small block chevy so it will also be more reliable while making more hp. The windage is also much better. :chevy

 

Now who told you that ;);) (or who told me that!)


Chris


[Modified by ChrisB, 2:21 PM 1/17/2002]

 

I built my SBC427 using a tall-deck Dart Iron Eagle block. Dart actually makes the "Rocket" block for GM - they cast and machine it. The Iron Eagle is identical to the Rocket block except that the Iron Eagle is capable of being either a wet or dry sump, depending on how you plug it, whereas the rocket is offered under two different part numbers depending on if you want a wet or dry sump.

I used part number 31122222, which is a tall 9.325" deck block, with splayed steel mains, 400 main size, and Big Block cam bearings. All of the blocks feature a .391" raised cam, and .800" spread pan rails, .400" each side.

Contrary to what World Products/Bill Mitchell Hardcore implies in their advertisements, the use of a raised cam and spread pan rails does not require expensive race only hardware. Summit offers a pretty decent Moroso oil pan for this block in their catalog for $250, and Stef's can make you a custom sheetmetal aluminum pan for it for around $300. These are both good pans too, with kicked out saumps, teflon screens, trap doors, and include the pump and pickup I think. Felpro offers pan gaskets for it for about $25.00. As for the raised cam, Cloyes offers a Tru-Roller timing chain for it for about $95, and a stock timing cover and gasket fits it just fine.

Even the tall deck, if you chose does not add alot to the cost. Dart sells the necessary spacers for $40, or you can use one of their single plane intake manifolds that are designed for the tall deck blocks - and convert it to EFI if you chose. You don't have to go with a custom Hogan's sheetmetal intake manifold like I did if you don't want.

I have also helped two guys build SBC 427's based off of the HArdcore Motown SBC427 shortblocks. They are good blocks and the shortblocks are a rpetty good deal if you're satisfied with the quality of the components he uses. My only reservation is that there have been reports of the main webs cracking around the 1/2" main bolts/studs. There isn't alot of material left on the sides, they didn't widen the mains to accomodate the larger bolts/studs. I heard they were going to go back to 7/16" mains bolts/studs, so maybe they did if there is a Motown II block out now. This has only been a problem on very high output motors (like 800hp+), so it porbably isn't a concern if you're just gonna built a typical 600hp/7000rpm street or street/strip motor.

I don't know all the specific details of the Motown blocks, but the Dart block is what I'd recommend based on having used a couple of Dart blocks myself, and having helped build some Motown blocks - plus what I've seen in the NMCA/NSCA scene.

If you want all the specs on the Dart block, they are detailed on my webpage

http://www.montygwilliams.com . go to Engine, then Block.