carrman
Senior Member
440 Source heads are straight plug. I wanted to run Sidewinders, but they are angle plug heads also.
Well, this is bad.
- Thread starter carrman
- Start date
70bigblockdodge
Old Man with a Hat
Have them CNC ported or your car is going to slow down. Those 346 heads are done very nicely, stock ootb 440 source will most likely not flow as well. Better than a stock head, but your 346s are not stock head. The other option is to make one head the same as cracked head. If you pull the cracked head and take it and a virgin head to someone who knows what they are doing and tell them to make it match flow wise.
That 1.88 exhaust valve is old school. Most current tech is using larger intake 2.19 and 1.76 exhaust and just improving exhaust port shape to get the numbers(eliminating all the wierd bumps) most likely where yours cracked when removed by porting
carrman
Senior Member
Well I’ll have to see if anyone around here can replicate this. The heads were ported to get them to flow at 260cfm
73Coupe
Senior Member
What does the crack look like?
carrman
Senior Member
I have to find out, but my mechanic only saw it being underneath the car when it was warmed up and running.
carrman
Senior Member
Can someone break down for me what exactly the problem is with using and angle plug head with the HP manifolds??
70bigblockdodge
Old Man with a Hat
The plugs angle toward each other 1-3, & 5-7. Where the exhaust pipe flange comes down between 6-8, the plugs are pointing toward the section above the flange. With C body hp drivers side I think it is the same way.
carrman
Senior Member
So are they then impossible to get to?
70bigblockdodge
Old Man with a Hat
Here
carrman
Senior Member
70bigblockdodge
Old Man with a Hat
I cannot remember where the C body pipe flange is. My E body driver side would be okay because the outlet is all the way at the rear.
Put headers on it, two birds one stone.
carrman
Senior Member
No headers.
70bigblockdodge
Old Man with a Hat
I have been were you are now. My 440 had 906 heads with 2.14 and 1.88 stainless valves, hardened seats and bronze guides. They were built back in 96 on my fresh 440 at the time. I was using the HP manifolds as well. Fast forward to 2011 and my heads developed the same cracks that yours have. Heads were junk and I had 2 more sets of 906 heads. It cost more to redo another set of heads to that same level even though I already had heads and a full set of Manley pro flow valves. I purchased the 440 Source Stealth heads and there rockers. I had to get custom pushrods made because of the rockers but everything went together great and worked real well with the HP manifolds.
My 4767lb 4 dr 1966 newyorker went 12.60 with stock out of the box stealths. I later had them cnc ported and it goes 12.20 now with no tuning. This is all after i drive it 80 miles to the track. Here is a few 12.80 passes with the stock stealths.
PurpleBeeper
Member
I've been looking at a similar issue myself on a b-body that has older Heddman headers. The only thing I can think of to minimize the clearance problem with angle-plug heads (other than denting a header primary tube) would be to run the "shorty" yellow Accel spark plugs + some "heat socks" + old Direct Connection multi-angle spark plug ends on the close plug wires. I'm not sure how much that would help with stock manifolds.
It's hard to tell on the picture exactly how bad the plug/manifold clearance issue is on #8 (especially not in the car), but if you can protect the plug wire from melting AND get "some type" of wrench in there to change the plugs, it would be OK. All of this is just speculation on my part.
Another idea/question....How thick is the cast iron in that part of the manifold? Could you grind out a little more plug/wire clearance?
Lastly, headers are not "easy" to put on, but most "aren't that bad". At least on b-bodies, you just jack the car WAY up in the air & sometimes have to lean the motor over a little to put them on. Smaller primary tubes & "slip tubes" are your friends in tight situations.
70bigblockdodge
Old Man with a Hat
Just use the steaths they look right they flow better than stock with some porting they can feed a 500" as MEV has proven. Use your valve springs or replace them while your here, and good retainers and locks. Plus you will lose 44# off the nose.
Those are 650 possible horse heads Mark, nice.
Those are 650 possible horse heads Mark, nice.
The big issue with C-Body headers with a 440 is that there is very little room to replace the header gaskets when they inevitably blow out. I tried about every gasket on the market and none held for more than a few months on a daily summertime driver. Finally gave up and put the stock high performance manifolds back on. The PIA of changing the gaskets on a regular basis was more trouble than it was worth. Car was a '69 sport fury.
Dave
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