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fair enough, I guess if theres no other performance improvements in the newer one then theres no real need to keep it!

Yeah the vt manifold is all different same as the vt's run different engine belts ect

It'll need a re tune with vt motor though. The vt have the v shape in the head combustion chamber which increases the comp ratio from 8.4:1 to 8.8:1

The VT manifold is the exact same casting as the VN-VS except for 3 holes not being drilled for temp sensors and a vacuum port.

Yeah everything's still the same in that sense. Even the heads are the same besides the v shaped chambers. Looking at the roller cam specs I think there the same as well. But I did hear someone say that the cam is different other than the obvious being a roller design they may have different ramp rates?

It's interesting to look at the difference between essentially the same motors. Would seem the biggest gains were from compression increases. Vs clubby 8.4:1 comp 185kw, vt 8.8:1 comp 195kw and those vn's that were factory fitted with flat tops are 9.0:1 and rated at 200kw

Roller cam would have more lift and more aggressive ramp rate even if it has the same duration as the old flat tappet cam.

I would have thought those 200kw VN motors had a slightly bigger cam as well. Some of those engines also had the D shaped exhaust ports.

edit: Just had a quick look at the Crane catalogue, they list the H268 as the SV5000 replacement cam (206°/206° 112lsa .448" lift) and the H276 as the replacement Grp A cam. The biggest issue with the stock 304 has always been the lack of compression to do a decent cam swap

edit 2: (getting a bit sidetracked here so) the roller cam would have helped to reduce engine noise for the new engine management system which would rely more on the knock sensors.

edit 3: I was kinda trying to get back on topic with the wiring for the knock sensors bit which the original 304's never had (I beg for forgiveness Master Sensei).

The difference in output between the hydraulic flat tappet engines and the roller cam engines mostly comes from an increase in valve opening under the cam curve. The more valve opening you have the more air you can get into the cylinder. The more air you get in the cylinder the more fuel you get into the cylinder. The more fuel you get in the cylinder the more power produced from that cylinder. Roller cams offer more valve opening under the curve compared to similar spec (lift/duration) flat tappets so you get more air > more fuel > more power.

Question, how does this all relate to VS V8 PCM wiring diagrams?

Doing some wiring for a VS Ecotec conversion dual thermo fan's no BCM. Anybody know what pin is used for the second fan in this case?