***** I NO LONGER OWN OR RENT THIS JIG *****
I kept this page up for informational purposes only!
Dodge Magnum Cylinder Head Drilling Jig
This is a jig that allows you to drill a standard Chrysler small block intake manifold pattern into a Dodge Magnum cylinder head. Magnum heads utilize vertical bolts to secure the intake to the heads unlike the older LA heads that had the bolts at an angle. Either pattern can be used once the new holes are drilled and tapped. To date, this jig has been all over the US and Canada and has been used by over 50 people with excellent results. Prior to Magnum-specific 4 barrel intakes being available, this jig was the best and easiest way to use the superior Magnum heads on your small block. It still is a viable option for the budget conscious guy looking to swap heads and retain his existing intake or for adapting a factory six pack intake to a set of Magnum or Magnum R/T heads. This jig was constructed using an LA360 head as a jig and carefully welded up and braced. The first set of heads to be drilled was my own set of Magnum R/T heads (even though I already owned an MP Magnum 4bbl M1 intake!).
It bolts to the accessory holes on the ends of the head. It fits pretty tight to the head. The bolts will not thread in if it is not aligned just right. It can be wiggled/rotated into place with a RUBBER mallet or a dead blow hammer. The tubes a 3/8" ID steel tube and to eliminate wear in the jig itself, I line the tubes with a 2-1/2" piece of copper tubing for each head I do. The copper tubing is 3/8" OD and 5/16" ID...the size bit most tap sets come with. It is available at just about any hardware/home improvement store. This lets the copper be the wear surface for each time a hole is drilled and not the steel. Poke them out and poke new ones in for the next head. I just bought a small roll of copper tubing and use a tubing cutter to cut the pieces.
Materials / Tools:
1. Electric hand drill
2. Good, sharp 5/16" drill bit (2 would be a good idea)
3. 3/8" OD copper tubing
4. Small tubing cutter or hacksaw
5. Three good 3/8" bolts (I used 318 intake bolts)
6. Oil - for lubricating/cooling the drill bit
Since this is an el-cheapo solution to a common problem with us Magnum head users/wannabe users. I won't rule out the possibility that you may need to rat tail file a hole or two in your intake to make it fit 100% correctly, as I am not the one doing the drilling and tapping. I also can't take responsibility for you doing something dumb and breaking a tap or a drill bit off in your head.