I am putting together a new [to me] short deck 540 with the following parts
GM GenVI 502 block
Callies 4340 4.25" steel crank
Std bore 4.5" Flat top forged pistons
Callies H beam rods
Dart Pro-1 24degree 355 CNC Ally Heads, 121cc chambers Manley Stainless and Inconel valves
Compression ratio approx 10.25:1 [Running UK 98 RON fuel super unleaded fuel]
Closed cooling system
Vic Jnr intake
Holley HP-EFI 900CFM / 85Lb injectors with O2 and Knock sensors
Eickert thunder and lightning cast ally header dry to the tip and 5" GGB wet mufflers on the back

I have a choice of cams
The motor comes with Comp Cams XM284-HR 11-451-8 - Xtreme Marine? Retro-Fit Hydraulic Roller Camshafts and solid roller lifters

Or I have a custom ground cam that Bob Madara made up for my 454 Magnum with std 8.6:1 compression and 088 iron heads and the intake and exhaust above with a set of Morel [PBM] hydraulic roller lifters and good springs/scorpion roller rockers.

Grind; XA.226.360.230.350.13

Lobe separation = 113 Cam deg
Valve Overlap = 2.8 crank deg

Intake
Valve open = 4.9 ‘BTDC
Centerline = 108 ‘ATDC
Valve close = 41.2’ ABDC

Duration = 226.1 crank deg
Lobe lift = .36035”

Valve Lift = .6126”
Lobe Area = 27.72”

Exhaust
Valve open = 52.5 ‘BBDC
Centerline = 118 ‘BTDC
Valve close = -2.1’ ATDC

Duration = 230.4 crank deg
Lobe lift = .35067”

Valve Lift = .59614”
Lobe Area = 27.76”

Firing Order swap 18726543

I get a bit lost when it comes to cams and would like some input - what would the likely differences in power and torque delivery be between these two cams? and at what revs?

Are either of them suitable or would something else be better with these heads and intake?

How does this build look, are the parts chosen reasonably well matched?

Thanks

I'm not an engine builder, just tossing out some thoughts, std bore I believe is 4.47, going to 4.5 should give you the opportunity to get the bores straight. Wondering if the 335 cc head would be better on a 540. To me, both cams look better suited to the 454 than a 540. I'm sure someone will correct me. Good luck with your build.

Both cams too small for a 540. Unless you dont want to spin it past about 4800rpm.

+^^^^^ agree and i would go with the 335s if using dart heads.i have the 355s on my 588s.

Happy holidays everyone , I think your static compression figure is slightly off with the specs you're giving for the heads and the bore and stroke even at a .000 deck your compression is at best 9.5:1 and if you're planing to cam the engine you have to be sure on the compression ratio. Also check your choice in cylinder head the Dart pro one is a good piece and priced very good as well but the AFR head is a way better choice. We have a package we sell with the AFR heads and a bit more cam then what you have in mind and it makes 750HP and runs on rec. 91 here in the US. Best of luck and keep us posted. Sincerely Laz Mesa