I am in the middle of researching for parts on my L92/L76 build and wanted some opinions on things.

Using a 6.0 iron block

First off would be I plan on a totally N/A motor that being said what would be a better route a 408 or 418 i know there really isn't a whole lot of difference there but any little bit helps.

Also I plan to have the l92 heads milled to 65cc chambers will i run into any Piston to head clearance issues on a 418 I will have the block decked some.

Another question is I really only planned on having a little exhaust port work done on the heads them self so would they be enough to even supply a 418.

 

There's not much difference, but I'd keep the motor oversquared (bore bigger than stroke). A 408 is a 4.03" bore and a 4.00" stroke.

You should never have PTV clearance issues on a new motor as long as you use pistons with valve reliefs in them. The stock LS1s use flat-tops... that's why you have to be careful with clearances.

The stock L92s are enough to support a 408. Some worked L92s should be completely fine.

Mike

 

Anytime you build a motor and use milled and molested heads you must make sure that there is no PTV clearance problems...Ultimately, it comes down to the cam selection and valve size...And as we all know, cams for the L92 setup are a bit different than those commonly found in LS1 style heads...So pretty much what you need to do is call some people who might know the answer...You don't want to guess at this, and definitely use some clay and mock it up to see if you might run into problems before you run a motor that could potentially cost you money because you were lazy...