Chev 350 gurus (help required)

[dzorde]

Guys,

In an earlier post I wrote my TPI chev 530 pinged on pump leaded with 4deg
static advance.  Now I thought it was due to too high a compression, and so
I've finally done a compression test.  The engine is standard flat top
pistons and 520 iron headswith 1.5 ratio roller rockers, 305 TPI using
aftermarket speed density ECU.  The compression test was as follows:

Cyl 1, 3, 5, 7 between 237psi and 240psi
Cyl 2, 4, 6, 8 between 223psi and 227psi

The cam specs are:

inlet opens 23btdc, closes 61 abdc, duration 264deg, cam lift 0.269"
exhaust opens 68bbdc, closes 26atdc, duration 274deg, cam lift 0.285"

I was told by an expert to put in a bigger cam to bleed of some pressure and
get down to 210psi.  I didn't tell him the cam specs, but he recons I have
an economy cam since my compression is so high.  The same guy also says the
pinging could be due to the advance springs in the dizzy softening when they
get hot and give just that little bit too much advance (need to check full
range when engine is hot).

Now here are my questions:

1.  Is this cam an economy cam ?  The guy that ground it said it would be
perfectly suited for a TPI speed density system (I think so too, got lots of
power up to 5300rpm, then it runs out of power quite noticeably).

2.  Can you calculate the compression ration from the psi reading ?  If so
what is the equation ?

3.  If I need a bigger cam, any suggestions ?  Don't forget a standard TPI
is only good for around 5500rpm.

Help appreciated

Dan     dzorde at geocities.com

P.S. next thing to try is a tank full of BP100 racing fuel.