Blue 202 build, need help understanding cams please

[Brownee]

Mornin'. Try to cut it short guys, I'm building a mild straight gas engine along the lines of what I read in kmacs answer to this thread http://www.performanceforums.com/for...-67222874.html

Duggans in Reservoir are doing the work, the comp ratio will be 9.8. I have a cam from previous build, unknown brand, the stamping says, CWC and FO1 and EP35. spec sheet states, Dur.@.050" 210
421thou lift. 28/65IN. 68/29 EX. Been told its a mild gas cam.
Jmac suggests either a Tighe 440t, http://tighecams.com.au/profiles2/ho...lhydraulic.htm

Crow 35602, http://www.crowcams.com.au/search.as...35B&MK=13&PC=0

and I looked at Wades 242a,http://www.wadecams.com/PoProf/cat.pdf

The EX figures on the cam I have are way different to the Tighe being 70/20 compared to 68/29 on mine, yet the characteristics are similar in every other aspect.
Is staying open on the EX side a gas thing or what?
My cam has a wear mark exposing a porous or cast type look at one half of the lobe, the boys at Duggan arent keen at all so it needs rebuilding.
These are the options, rebuild or buy, money isnt the issue, understanding these similar yet different mild cams are and the why factor. Why close the EX so late on this cam? To suck more gas on the inlet stroke? I've done a lot of reading but I just dont seem to grasp the knowledge somehow.

Also need to know if the bonnet needs modification on HX for EFI manifold to fit?
Thanks gents

[Terribleone]

EFI manifold should fit no worries, I had one in my LJ and they have far less room under the bonnet than a HX.

[Brownee]

Thanks mate. Rang Crow they set me straight what I had wasn't a gas cam. Their 666 is.