ATK Engines DO11: SBO 350

[foxtrot]

Its nice to see that Jegs has SBO engines listed in their crate engine lineup! Maybe you could contact ATK directly to see if there are any options to bump the compression & upgrade the cam?

 

[olds307 and 403]

The 403 is only a concern if you are spinning past 5000 RPM. The heads do suck awful but the 403 is an easier upgrade and has a significant advantage in low end torque, was 50 ft/lbs stock to stock. The 350 will probably have similar power compared to a 5A 307. As long as it is a solid main block and #8 or any of the earlier heads, it will be an easy upgrade. Run it till the warranty is up and then a set of Mahle or DSS forged pistons, depending on which heads and a set of the just coming out Scat SBO rods along with a cam, if you are not happy with the power output. It sounds like you are planning on replacing the awful stock exhaust, that alone helps a lot. Good luck, at least there is a warranty if things go south.