FYI, Volvo sold 3 different thickness B18 head gaskets, .8mm, 1.6mm and 2.4mm, but only 2 B18 cylinder heads and both heads have the same thickness.

The difference in the heads is the size of the combustion chamber.

There are 4 ways to adjust the compression ratio.

1. Head gasket thickness
2. Increasing or decreasing the combustion chamber size
3. Piston/crankshaft modifications
4. Camshaft overlap

And there is absolutely nothing wrong with a D cam and in fact Volvo recommended the D cam as an upgrade for the B18 in their "B18 Tuning Guide".

We are so dedicated to the D cam that when the high quality D cams made by TRW in Europe were discontinued, we bought an original Volvo D cam and used it to make copies. And it's the only camshaft we almost always have in stock.

BTW, IPD cams are made by Isky and IPDs torquer cam is an Isky VV61 and their street performance cam is an Isky VV71.

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Eric
Hi Performance Automotive Service (formerly OVO or Old Volvos Only)
Torrance, CA 90502
hiperformanceautoservice.com or oldvolvosonly.com