Marc Sayer is the proprietor of Performance Engineering, his company specialises in performance parts and modifications for Z's. No doubt he can tell you more if you contact him directly. Over the few months since he joined the net he has shared valuable technical know how with us. I have had to make a seperate page to index his articles and discussions he was involved in.
Please note: This is not an endorsement of his products or an advertisement, rather it is a sharing of information in the same spirit as Marc shared it with us.

Marc's contact information is: Performance Engineering, 1070 W. 2nd Ave., Eugene OR 97402, Phone, (503) 484-0904 Fax 746-0863, msayer@efn.org

He has also put a catalogue on the World Wide Web. Check it out.

S.U carburettors info
Notes on Redline MTL for your Z's gearbox.
Changing your differential and transmission oils.
On oil pumps.
On multi electrode spark plugs.
On roll cages and strut braces for your Z.
On running strapless diffs.
Torquing engine studs.
Air Horns.
On carburettor and distributor problems
A brief discourse on vacuum advance.
A very interesting discussion on vacuum advance between Andrew Levy and Marc.
Further discussion of vacuum advance and carburettor tuning.
On crank pulleys and harmonic balancers.
On suspension.