8620 Steel Main Caps
Jim Smart
July 18, 2014

Aluminum Block

If lightweight aluminum is more to your liking, Bear Block Motors has your FE block. In paint, it is challenging to tell the Bear aluminum 427 block from iron because it is cast basically the same way cosmetically with all of the correct markings. It weighs just 125 pounds, remarkable when you consider the weight of an iron block at 250. What’s more, the Bear aluminum FE block is priced just $1,200 higher than the iron, which is somewhere around four grand. If you perceive the new FE as pricy, price a used 427 side oiler block and be ready for sticker shock. Prices on both iron and aluminum blocks have not yet been confirmed.

On Top…

With such a grand slam block casting for FE enthusiasts, you’d expect Bear Block Motors to complement this block with a world-class cylinder head. It has with the high-swirl aluminum FE cylinder head in as cast and machined or in CNC ported. This is the FE cylinder heads brought to current engineering standard high swirl, good quench 72cc chambers, 11⁄32-inch valve stems, 2.150/1.680-inch intake/exhaust valves, 300/225cfm intake and exhaust volume, and bowls cast to match valve seats perfectly. Extra thick port walls allow for additional porting if desired.

There’s also a CNC-ported FE head available from Bear Block Motors with 2.250/1.750-inch intake/exhaust valve sizing that offering a whopping 355/250cfm intake/exhaust volume. These heads mandate a 4.230-inch bore.


When you compare the Bear Block Motors castings to original Ford, they aren’t in the same league because casting technology has changed significantly in 50 years. Here are examples of original 427 castings.

11. Steel cylinder sleeves are siamesed for extraordinary strength and stability.

12. Head on, it’s tricky to tell the Bear 427 from an original with the exception being high casting and machining quality.

13. Indestructible 8620 steel main caps with studs and alignment pins yield stability like never before.

14. Throw a coat of paint on this and it’s virtually identical to the original side oiler 427 block.

15. The Bear Block Motors FE cylinder head is available in “as cast” and optional CNC ported. This high-quality casting is engineered for high-performance use and, as such, has been well thought out in every respect. We’re talking the more common 11⁄32-inch valve stem, 2.150/1.680-inch standard valve sizing (2.250/1.780-inch optional), high-swirl 72cc chambers with excellent quench to where you can run these guys on pump gas. Exhaust bolt patterns accommodate Ford compacts and intermediates as well as fullsize.

16. Check out these high-swirl 72cc chambers, which are the result of years of development to achieve the most optimum power-making FE chamber. Good valve shrouding. Large 2.150/1.680-inch stopcocks are standard. CNC porting optional.

17. Look at the evolution of Bear Block Motors cylinder heads through development. The GEN 1 head was a more traditional FE shovel chamber. With a lot of engineering time invested, the shovel chamber evolved more into the GEN 6 high-swirl chamber that made the final cut. A lot of time and thought have gone into the development of these heads

18. Here’s a 427 casting from the mid-1960s. Talk about a rough sand casting? Some 427 castings had these ribs while others did not. Cross-bolt caps required spacers.

19. Here’s an original 427 side oiler casting, easily identified by the side oil galleys and plugs.

20. Not all original 427 blocks were drilled for hydraulic lifters. This block isn’t.