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wireweld
08-27-2006, 10:25 AM
There is a pair of 915 heads on ebay,search under mopar 340 heads. Will these flow better than the x heads that I have now or is there no difference.

rumblefish360
08-27-2006, 11:24 AM
915 is the end casting numbers for X.J.O.U heads. They'll be the same, or should flow real close. Casting flaws and core shift aside, there the same head with a possible valve size difference at best.

perfmachst
08-27-2006, 04:57 PM
hello, the 894 head will outflow the 915 head. the 894 was made for a 2.02 valve. the 915 was made for `1.88, the factory bowl cut them or a 2.02 valve. i've tested them on my flow bench, seen the flow curves. guys running stock want them over the 915 head. just food for thought

rumblefish360
08-27-2006, 10:43 PM
I thought the 915 was a 2.02 valved head. NO?

72Challenger
08-27-2006, 11:31 PM
I thought the 915 was a 2.02 valved head. NO?
No, with one exception. The 70 T/A engine used 915 heads with special machining for the relocated pushrod holes. 68-71 the 340 used the 894 heads, which were 2.02 valves, the 915s were used in mainstream production starting in 71 on the 360 with 1.88 intakes, and in 72-73 the 915s were also used on the 340, again with 1.88 intakes.

rumblefish360
08-27-2006, 11:37 PM
Thank you, I sit here corrected. (Not standing, LOL.)

72Challenger
08-27-2006, 11:43 PM
What's the matter, your feet hurt? :)

Shaun
08-28-2006, 12:43 AM
There is a pair of 915 heads on ebay,search under mopar 340 heads. Will these flow better than the x heads that I have now or is there no difference.
894's were the X Heads(according to my info book).
Depending on which 915 SB heads they were(there were three-all with the exact casting number,but different date code),they could be the 340 six-pack heads(T/A),the 340 J heads(you would find a J near the exhaust ports by the head bolt holes),or the 360 J heads(which were also marked with a J,but had 1.88 intake valves).
So,both the T/A 340 915 head and the 340 J head(also 915) had 2.02 intake valves.From 1970-1972.:flame:
Shaun
-There's no replacement for displacement

72Challenger
08-28-2006, 02:04 AM
Seems like this disagreement is popping up again. I did make two mistakes, the '73 340 used the 587 head, not the 915, and the beginning date for the 915 on the 340 was '71. But the 340 DID NOT use 2.02 valves in the 915 head. I just verified from my factory Service Manual that the 1972 340 at least had ONLY 1.88 intakes. I'll have to leave it up to someone with a '71
FSM to be the final authority for that year, but I believe either of these to be accurate:

http://www.mymopar.com/headcastnumb.htm
http://clubs.hemmings.com/clubsites/cowtownmopars/CastingNumbers.html

rumblefish360
08-28-2006, 12:22 PM
What's the matter, your feet hurt? :)
HA hah a hah a.
Instead of, "I stand corrected" , I goof and say, "I sit corrected" since I sit at the computer. <g>

perfmachst
08-28-2006, 04:31 PM
hello, the 1971 340's used 2.02 valves in a 915 head. the 360 used same head with a 1.88 valve installed. all 68 to 71 340's had a 2.02 valve in them. the 72-73 340's had 1.88 valves. I bought an original 1971 340, and it had 915 heads with 2.02 valves from the factory. NHRA lists all this information and it comes from chrysler corp. they wouldn't allow a 1.88 valve head on a 1971 340 period. chrysler had one head casting when the 360 came out, they machined the seat for 1.88 for 360 or a 2.02 for a 340. in 72, all were 1.88 valve heads. its called cost cutting. just food for thought.ps, I had a pair of 915 heads ,2.02 valve with the Z cast in head here while back. they are an original set.

HNB racing
08-28-2006, 10:25 PM
dag perfmachst you are 100% correct you are good

john

George G. Leverette
08-29-2006, 02:09 AM
I am sure that is all correct, the 1972 Duster parked in the garage is a 340 car came from the factory with 2.02 heads and a forged crank. Maybe they goofed on the production line?????????????

345Dart
08-29-2006, 11:34 AM
perfmachst
So will a J head with 202/160 flow the same as an 894 given they are prepped the same? as my understanding is the ports are pretty much the same, just the valve sizing was reduced due to the smaller bore 360.
If any J head is better, do you know which one as I have 915As, 596s, 587s and the newre 308s.

perfmachst
08-29-2006, 04:46 PM
hello, in regards to the 915 vs 894 heads. I have a friend with an original 340/6 pac car. we tested the original 915/ 6pac head, a 915/with opened bowls to 2.02 and an 894 head. the 894 did out flow both of the 915 heads. not by a lot. the area under the durve, which is from .150 to .400 lift, is where the valve spends 90% of it's time.this area is critical for getting air in the cylinder. I found the 894 had a higher port velocity. for the later heads, the 587 is a very good flowing head!! the mopar SST. swirl valve will improve flow. i've had 308 on bench, the exhaust does flow very well. trouble is, it will out flow the intake up to .200 lift, this is the overlap area on a cam. the exhaust will pull some of intake charge out, causing headers to glow red.
it takes some of the intake fill away, lack of power, etc. the 308 were made for fuel injection, they don't flow wet air very well. just food for thought.
the 587 head with 1.88 SST valves have a very high port velocity. this is what fills cylinders!!

rumblefish360
08-30-2006, 12:31 AM
the 587 head with 1.88 SST valves have a very high port velocity. this is what fills cylinders!!
Will everybody please read this ten times now, then when your done, write it out 100 times, then read it 10 times a day, everyday, until they say nothing but....
2.02's on a 318 are not good for the street with dual planes and mild cams no matter who sez what.
Now that you read this far, go back and start to re-read this reply over and follow the instuctions again.
Heres the key words yet again!
high port velocity. this is what fills cylinders!!

Thank you and good night!

Shaun
08-30-2006, 12:50 AM
[/Quote]
2.02's on a 318 are not good for the street with dual planes and mild cams no matter who sez what.
Now that you read this far, go back and start to re-read this reply over and follow the instuctions again.
Heres the key words yet again!


Thank you and good night![/QUOTE]
318 CI,Dual Plane Mani and mild cam.... 2.02 intakes? Finally someone with some sense!
So here's what you do! Get some 2.02 intakes and build yourself a 318!:whack: Go Big,or Go home.
Shaun

rumblefish360
08-30-2006, 12:59 AM
Ha ha ha ha. Been there done that. 2.02's in a teen have there place.

TK
08-30-2006, 01:40 AM
YUp, at about 6500...................

LIsten to Rumble damnit.