1. It's always a good thing to lightly lubricate O-rings. Mkaes it easier to install and lessens the chance of damaging them. I always use a very thin film of silicon sealant. Acts two ways, it's rather slippery stuff when freshly applied. When it settles it acts as an extra sealant.
2.Put the pump cover in place. There should be only a rather slim opening between pumpcover and engine.
3. Different gaskets are there to get the proper clearance between impeller and pumpcover. This is needed to get the pump working properly.
Measure the gap mentioned under 2. First tighten the three coverbolts (fingertight)till the gap is even everywhere. Measure gap and add 0.25-0.50 mm to get the needed gasket thickness.
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<font color="blue"><i>1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (not very well known yet, but back on the road)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC
http://tr7beans.blogspot.com/</i></font id="blue"></center>