View Full Version : 300x Billet Head Mods

08-11-2012, 04:40 AM
To start out, here's my home made stud kit which was used on this install;


The MAD EFI heads I used had to be mod'd in order to allow the use of the port & starbord 300x PCM Temp Sensors, there was no provision for these probes at all when I got the heads. Head cooling cover plates were removed and the heads were clearance machined within the cooling passageway for the temp probe tips. These deeper drilled holes were needed because the probe was to long and would not allow the "O" Ring on the probe to make contact with the cooling cover plate thereby making a water tight seal. Along with this the cooling passages around the probes were cut deeper by .187" and widened by .300 to make up for the probes diameter in the middle of the coolant passageway, sorry no pic of that at this time, took one but it was trashed during the copy mode. Without this widening and deepening there would have been serious restrictions in water flow. Cooling top plates were match drilled and tapped for the probes. This mod was done on both heads as 2 probes are used:

This shows how tall the probe is bottomed out in the cooling passage;


Studs installed in block:

And here's the finished product, stud kit & heads bolted up ready to rock;

08-11-2012, 05:43 AM
Gary, Very nice work on both mods :thumbsup:

08-14-2012, 08:48 PM
Great job! Very impressive! :cheers:

08-14-2012, 09:12 PM
Nice job, I like the idea of home made studs.

How much compression?