Don't know the size of the valves but the exhausts look larger then my 1.60's. There is a listing that says the exhausts are 1.625 and the intakes 1.875.
Intakes don't look like they could be 1.94's but 1.94's definitely and 2.02 sometimes could be fit into a J head?
Some production heads you can fit 2.02's in, others you can't. It all depends on how accurately centered the valve guides are.
You can see in this shot that the valves almost touch. That means if the valve guide centers are off .010, they won't fit.
Most race head builders will tell you this before you start.
You can see how little space is left between the intake and the exhaust valves here. You have to measure that with a feeler gauge. Might be something like .020 for safety? I forget the dimension?
For production reasons there wasn't that much importance for holding the centers to blue print specifications.
The guides in my J heads were off enough that the largest intake valve that would fit with the 1.60 exhaust was the 1.94. Still very noticeable over the stock 1.78 and even the 1.875 in the 351w head.
The J head is a very good CORE to rework for bigger valves and ports. Some have bad mouthed it pretty severely but personally I consider those people very uneducated on the subject.
They are merely spreading misinformation.
Incidentally the 1.875 was referred to as the GT40 intake valve for a long time?
These GT40 heads were probably held to those blue print specs?
With 2.02's you get shrouding from the combustion chamber walls so their value starts to get questionable anyway?
If you look at the intake valve, look at the edge of the combustion chamber. It has been machined back to reduce the shrouding of the valve when it is open.
This would make one heck of a combination in a 'goose right Steve? I think you would need better headers though?
1-3/4" primaries if not more?
What I find ironic is that Ford re-introduced the name, GT40, to the '90s run of 5.0 heads.
People actually think they are these or that they are even in the same ball park? I suppose that is just marketing?
Sorry to have taken this thread off of topic. Hope the trip was worth it?
