Rob:
There are pros and cons to this idea.
Pros:
1. Higher compression = more power
2. Larger exhaust valves = more power
Cons:
1. Requires older, less efficient intake manifold (less power,
costs dollars to install)
2. Older, less efficient port design (less power)
Since either head will probably require a rebuild, I would
suggest an alternative:
1. Have your current head skimmed to raise the compression.
0.060" would get you to
about 8.5:1 (assuming this is the CR you want - you can safely
go higher).
2. If you can afford it have the head machined to accept the
older, larger valves.
The money for this would otherwise need to be spent swapping to
the older
manifold anyway, so net cost would be minimal. You may not even
need to install
exhaust valve inserts if your head shows no recession.
This plan lets you retain your emission fittings, the better
ports, and your existing
more efficient intake manifold. This will net you more power than
swapping the heads, and
you won't need to chase parts.
Just my $0.000002 worth.
Vance
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of Robert Houseknecht
Sent: Monday, September 13, 2004 5:36 PM
To: 6pack@autox.team.net
Subject: cylinder head identification
Hello To All:
I need some help identifing a head I have. I think it
may be from a '71 tr6.
The stamping is # 516323 with embossed #307837.
If this is from a '71 am I correct in assuming that
the compression ratio is 8.6 for this head?
I'm planning on using it on my '73 tr6. Is this a good
idea and what other info. will I need to do this?
Thank you in advance for any help you guys can give
me!
Also, I'm planning on attending the Bronte Creek show
this coming weekend if it doesn't rain. Hope to meet
some of the "Listers" there.
Rob Houseknecht
'73 Emerald
Check out the new British Cars Forum:
http://www.team.net/the-local/tiki-view_forum.php?forumId=8
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