Hi Guys,
If you're moving up from a stock 302 or built 302 with stock dimension heads (at the exhaust ports) to a Ford Racing 347 crate motor with the GTZ heads there are modifications to be made to the stock CAV headers.
The GTZ heads have raised ports and are 7/16 of an inch wider at the exhaust flange than stock dimension 302 heads. The solution was to make a spacer plate for our 302 dummy engine (so we didn't have to work on the customer motor) put the flanges in the same position as the GTZ heads and start cutting up the headers.
Although the port opening on the flage is correct, the bolt holes are inverted relative to the stock heads. We could have flipped the cut off old flanges, however the best way was to spring for the new flanges. Now were tooled to make them in .250 stainless for future conversions.
As you can see, there's no way the headers could be bent or forced into the collectors and the stock flanges were obscuring the top of the exhaust port. That'll cost a lot of ponies.
If your headers were supplied for a Getrag spec 302 and your going to ZF you will have to either splice and reweld your collectors at the muffler to fix the downward angle or do it all at once when fixing the tube lengths and angles for the raised port heads.
After cutting off 8 flanges, slicing the tubes into 17 peices, making up slices of stainless tubing and test jigging on the dummy motor we had it beat and ready to tig up.
It was a bit scary at first as these are not cheap parts to begin with and the stainless is really tough compared to mild steel, however once it was all done the results were worth it. We also picked up some additional clearance for the Weber Heat Sheild and Valve Covers making the whole setup better.
We can do this for you if you're faint of heart
Cheers
If you're moving up from a stock 302 or built 302 with stock dimension heads (at the exhaust ports) to a Ford Racing 347 crate motor with the GTZ heads there are modifications to be made to the stock CAV headers.
The GTZ heads have raised ports and are 7/16 of an inch wider at the exhaust flange than stock dimension 302 heads. The solution was to make a spacer plate for our 302 dummy engine (so we didn't have to work on the customer motor) put the flanges in the same position as the GTZ heads and start cutting up the headers.
Although the port opening on the flage is correct, the bolt holes are inverted relative to the stock heads. We could have flipped the cut off old flanges, however the best way was to spring for the new flanges. Now were tooled to make them in .250 stainless for future conversions.
As you can see, there's no way the headers could be bent or forced into the collectors and the stock flanges were obscuring the top of the exhaust port. That'll cost a lot of ponies.
If your headers were supplied for a Getrag spec 302 and your going to ZF you will have to either splice and reweld your collectors at the muffler to fix the downward angle or do it all at once when fixing the tube lengths and angles for the raised port heads.
After cutting off 8 flanges, slicing the tubes into 17 peices, making up slices of stainless tubing and test jigging on the dummy motor we had it beat and ready to tig up.
It was a bit scary at first as these are not cheap parts to begin with and the stainless is really tough compared to mild steel, however once it was all done the results were worth it. We also picked up some additional clearance for the Weber Heat Sheild and Valve Covers making the whole setup better.
We can do this for you if you're faint of heart
Cheers
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