I am considering having my factory heads re-done (due to money limitations).

It is my understanding that the factory heads flow around 165cc and most aftermarket heads are around 180-200cc (for TPI).

Again, this may be a stupid question, but can the machine shop modify the factory 165cc heads to be "made into" 180cc heads?

Would installing larger valves accomplish this?

Any info would be greatly appreciated.

Thanks!

 

What you are referring to is the intake runners. 200cc would be great for a larger engine, but I see nothing wrong with your heads. Have the machinist do em up. Im sure he can get them more near 180. Many cars are running the factory L98 heads,with some port work. Keeping your intake runners in the 165 to 175 area would be great for a "street", and somtimes "strip" head. With larger ports you give up port velocity. As for larger valves, in a stock iron head will most likely hurt flow or, not improve it at all. Keep the 1.94/1.50 valves and save money.

 

Thanks for the reply, brutalform.

You mentioned that I should keep my "intake runners in the 165 to 175 area ". Does this still apply if I add a TPIS Big Mouth intake & LTR?

Also, if the machinist is able to get the intake runners near 180cc's, does this mean I will have to use a special gasket and/or modify the intake manifold openings to match?

Thanks again!

 

Okay...put a stop on your plans...you mention "having the machinist..."...him/her doing the port work and rebuildng the heads will most likely far exceed the cost of aftermarket parts that will out perform (out of the box with no work) the stock 083's...$ per $.
Look into Dart, World Products, etc (in fact do a search for heads here and on the 'Net) and see what's out there.

Stticking with factory is good if:

You can do the portwork yourself and you're only paying for a rebuild.