318 timing chain.....and why the engine should come out.

X2 what rusty said
Edelbrock sells that cam because there's lots of profit in it
because it is almost backyard installer foolproof and it's available from Elgin cheaper
let's take a look at it
advertised duration is at SAE or with 1.5 rockers .004 278 intake and 288 exhaust
compared to the 268 @.006 comp xe268 it is still more seat duration
yet gives even less lift = 421-444 and area under the curve -
compare with the stock 340 cam (which has even longer ramps down .004 and below especially on the lobe close side)
compare with the 256 voodoo
now also look at the 10 degree extra exhaust- which you only need with stock heads without headers
remember this is a small block chevy cam as is the Comp XE 256, 260, 268 most all below the 274HL
It rev's good even with weak valve springs as it was designed 50 years ago when valve springs were not as good as today-
but it just does not breath as well as a modern profile
here's another thread
Thoughts on Voodoo 10230701 cam? | For B Bodies Only Classic ...
www.forbbodiesonly.com/moparforum/threads/...
I contacted Lunati for a suggestion on a cam to match my current engine components. I believe I have a lifter problem and hate the cam I have now (Edelbrock Performer RPM I think). Here is Lunati's suggestion and specs. Voodoo Hydraulic Flat Tappet 10230701 (that's big block)
Advertised Duration (Int/Exh):256/262 @.006
Duration @ .050 (Int/Exh): 213/220
Gross Valve Lift (Int/Exh): .454/.475

BIG difference in dynamic compression
check out bullet and Howards also, Jim at Racer Brown some have closer LCA than the 112 (if you need any more LCA)
no secret that I like Mike Jones version- it is real gentle on the open and close - has less real seat to seat- but then really gets with the program
but pricey and longer lead time