Here's another discovery.... When I pulled the main bearing saddle, I thought the main cap bolts looked different.... so I brought 'em home. Sure enough.... here's the SOHC 12v bolt head with weird markings:

Here's the DOHC 24v bolt - note the flange:

The bolt head markings indicate a grade 10.8:


I haven't yet pulled a SOHC 12v main bearing bolt to compare length and thread, but assuming they're the same, these will also go in the blower engine. <img src="/forums/images/graemlins/kewl.gif" alt="" />

The SOHC block is plenty strong as is and should be good for more HP than I'll ever attempt, so while the 4-bolt main '95+ DOHC VR4 block might be desirable, many of the stronger parts can be found in the cheaper Diamante DOHC 24v engine and it appears to me that the upgrades can make an even stronger SOHC 12v engine. <img src="/forums/images/graemlins/kewl.gif" alt="" />

Frank