Previous Thread
Next Thread
Print Thread
340 Heads, What's What #66329
05/30/08 05:47 PM
05/30/08 05:47 PM
Joined: Oct 2003
Posts: 3,378
KY USA
mopargem Offline OP
master
mopargem  Offline OP
master

Joined: Oct 2003
Posts: 3,378
KY USA
Hey folks I have a set of 587 casting heads w/1.88 intakes for my 340 engine that I plan on rebuilding back to basically stock 1971 specs. How do these heads compare to the 915 infamous "J" heads. Is ther really any diff other than some 915 heads have 2.02 intakes. Thanks for any input.


68 Polara 500...LL1 Y7 M6X
69 Hemi road runner...X9 X9 M6X
69 A12 road runner....R4 R4 M6X
69 ModTop FLORAL Super Bee...F
70 AAR 'cuda...EW1 EW1 H4X9
71 Duster 340...FJ6 V24 L6X9
71 road runner FC7 V1X M6X9

72 Rallye Charger B5 V1W

74 'cuda 360...KB5 V1X A6X9
08 SRT Challenger #234



Re: 340 Heads, What's What [Re: mopargem] #66330
05/30/08 06:00 PM
05/30/08 06:00 PM
Joined: Jan 2003
Posts: 25,200
Upper Midwest
M
MoparforLife Offline
Too Many Posts
MoparforLife  Offline
Too Many Posts
M

Joined: Jan 2003
Posts: 25,200
Upper Midwest
They will work just fine. Clean out the little holes by the exhaust ports real good and fill and level some JB weld. They will run just fine. The 2.02 valve heads may have a slight advantage if you use the higher RPM ranges. Basically the same head.

Re: 340 Heads, What's What [Re: MoparforLife] #66331
05/30/08 10:08 PM
05/30/08 10:08 PM
Joined: Oct 2003
Posts: 3,378
KY USA
mopargem Offline OP
master
mopargem  Offline OP
master

Joined: Oct 2003
Posts: 3,378
KY USA
Thanks, your probably right that they will work fine since I'm not building a race car here.I'm not seeing any pollution pump holes on these heads like later model 360 heads. My 340 is a 1973 and the heads look to be original with the motor, this motor is in my 71 road runner and looks to have been with the car for many years now, but needs a rebuild. I just want it to perform as well as a stock 71 340 does. I know that I will need higher compression pistons. Any more opinions?


68 Polara 500...LL1 Y7 M6X
69 Hemi road runner...X9 X9 M6X
69 A12 road runner....R4 R4 M6X
69 ModTop FLORAL Super Bee...F
70 AAR 'cuda...EW1 EW1 H4X9
71 Duster 340...FJ6 V24 L6X9
71 road runner FC7 V1X M6X9

72 Rallye Charger B5 V1W

74 'cuda 360...KB5 V1X A6X9
08 SRT Challenger #234



Re: 340 Heads, What's What [Re: mopargem] #66332
10/06/08 03:20 PM
10/06/08 03:20 PM
Joined: May 2006
Posts: 31
Pennsylvania, USA
340propak Offline
member
340propak  Offline
member

Joined: May 2006
Posts: 31
Pennsylvania, USA
Quote:

Thanks, your probably right that they will work fine since I'm not building a race car here.I'm not seeing any pollution pump holes on these heads like later model 360 heads. My 340 is a 1973 and the heads look to be original with the motor, this motor is in my 71 road runner and looks to have been with the car for many years now, but needs a rebuild. I just want it to perform as well as a stock 71 340 does. I know that I will need higher compression pistons. Any more opinions?




Can anyone tell me what those small holes below the regular exhaust ports are for on the 78 360 heads, do they have to be filled with jb weld? can i do it with the motor already installed in the car? I just noticed those after putting on a set of 340 hi-po manifolds, the regular 360 manifolds covered the holes.

Re: 340 Heads, What's What [Re: mopargem] #66333
10/06/08 03:47 PM
10/06/08 03:47 PM
Joined: Jan 2003
Posts: 25,200
Upper Midwest
M
MoparforLife Offline
Too Many Posts
MoparforLife  Offline
Too Many Posts
M

Joined: Jan 2003
Posts: 25,200
Upper Midwest
Quote:

Hey folks I have a set of 587 casting heads w/1.88 intakes for my 340 engine that I plan on rebuilding back to basically stock 1971 specs. How do these heads compare to the 915 infamous "J" heads. Is ther really any diff other than some 915 heads have 2.02 intakes. Thanks for any input.


They will run als well or better than the 915 2.02 heads till you start to spin in the 6000+ RPM range. The smaller valve will actually most times give you better low end. Too many blame the heads for the lower power output of the later 340 heads when in fact it was a combination of other things that did it, big thing being lowering the compression ratio big time.







Powered by UBB.threads™ PHP Forum Software 7.7.1