Exactly. I wouldn't doubt they are all a little different. They are a different casting as per the part and casting numbers.
If a X or J flows 250 @ .400, what would matter is I'll trade my Speedmaster heads for them even upIf a J head flows 250 cfm @ 400 lift.
and an X head flows 250 @ 400 lift.
Would it matter what letter is on the head?
Being I didn't build my engine, I have a similar situation, smaller chamber (I'm suspecting early semi closed chamber 273 on right side) but haven't checked casting number yet. 145 PSI cranking pressure right bank and 135 PSI cranking left bank, with the intake closing 107 degrees after BDC. Either that or the right head or deck had a pretty serious cut taken from it. I tell myself that the flow restriction of the semi enclosed chamber evens the power out the output of those higher compression (10.4:1) cylinders to that of the lower compression (9.9:1) cylinders.put a 2.02 X head on one bank, and a 302 head on the other bank.. that way you have the low end torque covered and the 6k rpm range covered. Talk about street and strip....
Check the port volume.
They're are differences.
Floors are different from each other. Took years to notice it.
If a J head flows 250 cfm @ 400 lift.
and an X head flows 250 @ 400 lift.
Would it matter what letter is on the head?
X is worth more to the restore guy.... To the performance guy, it's a guarantee that they get the 2.02. As far as flow, we could flow two X heads and they would flow differently. Casting on cast heads is far from consistent and perfect.Yeah some still think the X is worth more.
I think they are cast that way.Do you think those are cast in differences, or possibly so small that they are from the molds moving around or some such? In other words, do you think those differences are intentional?
I think they are cast that way.
X is worth more to the restore guy.... To the performance guy, it's a guarantee that they get the 2.02. As far as flow, we could flow two X heads and they would flow differently. Casting on cast heads is far from consistent and perfect.
keep your compression in the lo 9's with iron heads
was the gas better in the 60's and early 70's ?Why? When 340, 383, 413, 426w, 440 and hemis came from the factory wirh 10 to 12.5 to 1?
Very true.Exactly. I wouldn't doubt they are all a little different. They are a different casting as per the part and casting numbers.
The headers are the shortest leash on that dog.Thanks for all the feed back everyone. I was wanting to build a 400 hp 360 . I have lots of old issues of mopar muscle and mopar action but one issue of mopar muscle has an article about a guy that likes to take mostly stock parts and a few after market parts and he made 378 hp with: thermoquad,comp cam , J heads that had a light porting /polishing etc. After market flat top pistons and headers. My project 65 dodge dart 2 door post car weighs in at around 3300 Lbs give or take. I figure for a daily driver and once in awhile to the drag strip on amateur night a mostly stock 360 with performance cam 4 barrel , flat top pistons 10:1 compression , 360 J heads with ports gasket matched valve job bowels cleaned up ,air gap dual plane intake shorty pretzel headers from hedmen headers, 904 with racing guts full manual valve body, 8-3/4 with posi and 3:91 gears should be more then plenty for that little Abody car ?
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Big time better. Nothing like the puppy pee we have nowdays.was the gas better in the 60's and early 70's ?