Lpg/unleaded heads

[commy vk]

I Have replaced the existing head on my commy vk 84 model with a lpg/unleaded one,hardened seats,K line guides etc.
I can remember when the country changed to only unleaded fuel as I was using the old super grade,high octane.
There seems to be some ppl out there that believe that the vk factory head was designed for unleaded?
Can someone verify that this is not the case?

[DANNY8]

Nah don't think so.....the way I see it, the VK didn't have a cat so wasn't designed to run on ULP, so doubt the head would of been either.

[VNracer34G]

Regardless of whether they were designed for it i know for a fact they can't handle it and seat recession is a real problem on the exhausts - i did heaps of them when was working in machine shops years ago - gave up measuring the stems on the ex. valves after a while as they nearly always had in excess of.003" stem wear and they get thin on the heads too. Did you get the springs done while you were at it?? they are usually soft and ready for the bin after years of use.

[VK SL 3800]

The owners manual states you are so supposed to only use super, so they are leaded only.

[commy vk]

Thanks for the replies good onyas,regarding as to whether the springs were replaced I would assume they were,well I hope they were?
It was an off the shelf swap over wrapped in plastic shrinkwrap.
I thought I might just have needed new stem seals which I did replace but the car still blew huge clouds of smoke at start up (which I was told was a sign that the seals/guides were worn)