ok so here we are 2020.. I have the chance to get either 9 thread stock heads or 4 thread pnp heads with new everything. I am doing a single turbo built 8,000 rpm Sullivan lower/hpp upper with custom cams... So the question is to go with the ported heads or stick with the 9 threads? need your guys input on this subject. I have read old post with back and forth reason too and reasons not to. I am at 300 to 400 price difference on the 2 so money is not a big concern.
ported heads or not?
- Thread starter termcobra281
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personally I dont feel like properly torqued plugs in 4 thread heads are a problem. Since the heads are off you could always have 9 thread inserts put em in - make sure to use aluminum and something like lock n stitch which have a mechanical means of keeping the insert from backing out unlike a helicoil
do you know what the price is on those type?
For your build I would with out a doubt get P&P heads. Yes someone will come on and say "my buddy made 3000rwhp with stock heads". The fact is your engine will be more efficient and will make more power with P&P heads. I agree with either doing inserts or wait and find 9 thread plugs.
I wanna say 200-300 bucks but it’s been a few uears
think I am seeing the kit for around 500
I would go with ported heads it'll help for sure. I just had Fox Lake port a set for my new engine.
I'd definitely go with ported heads. If you're running higher boost (20+lbs) I wouldn't go with the 4 thread heads. I've had conversations with John Mihovetz and Ron at Fox lake and both advised me to go with 9 thread heads. The quotes I received on fixing the 4 threads to hold boost made me believe it is more cost effective to buy a set of 9-threads to start.
I believe thats what the shop charged to do it when they were building the motor
Mihovetz told me when going turbo you need to replace all the valve guides because the factory stuff clearances are too loose.
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