A slightly different version of Patrick G's cam
 

I am trying to pick between two cams for 2.5 PRC 5.3s. I am aiming for a 6300-6400 shift point at most. The first is a 223/223 with LSK lobes on a 110+2 using 0.045 gaskets. With the VE spreadsheet that ends up having a 39.5 IVC, 43.5 EVO and a DCR of 8.80. The second is a 227/227 with LSK lobes on a 110+4 using 0.045 gaskets. That ends up having a 39.5 IVC, 47.5 EVO, and thus the same DCR of 8.80. Will either or both of these meet my needs of a powerful street cruiser that will only see the track 2-3 times a year? If both do, which do you think would better match the heads? I know the 223 would have a better midrange but the 227 will be slightly better on the top end. Which would give the best power under the curve? I am kind of stuck on these two because of the relatively low overlap compared to a split cam of the same size and since I don't need to carry the power very far past peak with the low shift points. Will that DCR be too high for 93 octane?

BTW this combo will be used with a SS3600 or SS4000.

Both will be excellent at meeting your needs. The 227/227 will make a little more overall power. Your actual DCR is going to be lower than 8.8:1 though. The 227 lobes check in closer to 279@ .006". Use this for your DCR calculations and you'll find it in acceptable range for 93 octane.

hmm I didn't know that about the LSK lobes. Now I end up with a DCR of 8.73 :) Thanks! Anyone else? I don't think I have seen anyone yet with these exact specs?

I have a 402 HR cam that is 278/278 Adv Dur., 239.75/239.72 @.050 Dur., 109.9+2, with .627"/.627" lift with 1.7 rockers. I'm not sure if that is what you meant though.

240/240 is much bigger than what I am looking for but thanks. What is everyone thoughts about using a .040 gasket to achieve a DCR of 8.84? Would that be too high for 93? Will there be any PTV issues with the 227 and these heads?

That is alot of lift. What springs are you going to use? If you go with the .040 you will have a better quench. Which should help with knock.

The springs that come with those heads are rated at .660" so I think I would be ok?