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Heads on my 360?

  
Mopar Muscle
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Heads on my 360?

 
19plymouth64 19plymouth64
New User | Posts: 3 | Joined: 01/13
Posted: 01/11/13
11:38 AM

I have '64 Belvedere with a 360 that is consistently running around 13.4 @ 100 mph (2200 ft above sea level). I would love to see 12.9 eventually. The current set up has 2800 stall converter, 3.91 gears and a 27in tire. The engine is 40 over, has about a 9.5 c/r, Edelbrock Air Gap, Holley 650, Mopar Purple .484 cam, and small valve 360 heads with a little porting and back cut valves.

I figure I could definitely pick up a little with some changes to the current heads. I'm hoping to get some opinions as to whether I should put some money into my current heads (2.02 valves, more port work, etc.) or if I would be better off putting the money towards something like a set of Indy LA-X heads.

Also I have been told recently that the Mopar Purple cams are still ok, but are "old" technology and there are better cams out there now.  Any thoughts?  

drmopar drmopar
Guru | Posts: 1445 | Joined: 02/08
Posted: 01/11/13
05:11 PM

13.4 in a B body at 2200 ft. is a respectable ET. Breaking into the 12's will take money and probably a new combination of parts. Since your talking about buying LAX heads I will assume you have a LA setup. You suggest you have 9.5 comp. Have you done a static comp. test? You should, it needs to be about 150lbs cranking pressure for a street/strip LA motor to live on 91 octane.
Here is what I recommend, keep the heads you have if they are ported and polished 340/360 LA's. If the comp. is below 130lbs you can cut .030 off the heads to get the stat comp just over 150lbs. If your current comp. is 140+  install the thin mopar head gaskets. Every 10lbs of extra cyl pressure is worth about a tenth of a second in the quarter on the small blocks. 2.02 valve upgrade? Recommended.
Cam? The old 484 cam is good but there is better. Most of the guys running 340/360's at our local track run solid cams.  A Comp. cams 236/242, .501/511 unit is an amazing street/strip cam and worth at least 2 tenths over the mopar stick. However if you want to stick with a hydraulic cam the comp cams xe274 Hydraulic makes similar HP with about 20 ft lbs less torque in the 4000-6000rpm range which affects ET. Obviously an adjustable valve train is needed with the solid cam. If you install the solid cam I like to advance it 4 degrees+.
converter, gear, tire, intake and carb are well matched for your current set up and may very well work with the above recommendations. However the real secret to a quicker ride is 60 ft times. This is critical in a B body A motor combo to ET. You need to aim for 1.80 second 60 ft. times. I have personally run 12.9's at 101 MPH in my old B body 360 combo. It took a similar motor, however it was matched to a 4000 stall 9 1/2" Dynamic converter with a 28x10 slick and a 4.30 gear.
Good Luck Cool  

19plymouth64 19plymouth64
New User | Posts: 3 | Joined: 01/13
Posted: 01/11/13
10:58 PM

Thanks for the the input. I really appreciate it. That sounds like a good plan. I guess if I really want to make sure I see 12's I should sneak over to my dad's place and "borrow" his 408. He won't notice, right? Wink  

451Mopar 451Mopar
User | Posts: 220 | Joined: 07/10
Posted: 01/12/13
01:52 AM

You could do larger valves and porting of the stock heads, but if it's in the budget, I would just go with the aftermarket heads.  My reasoning is after spending time and money on the stock heads and maybe running the number, then when you want to go quicker, you'll be back at the same point of upgrading the heads, so why not just go with the new heads.
Also, a good high-stall converter is worth investing into.  Expect to pay $500+ for a good converter.  

drmopar drmopar
Guru | Posts: 1445 | Joined: 02/08
Posted: 01/12/13
03:30 AM

Lots of 360's running 12's & quicker with factory heads. Lots of 408's running 11's with factory iron heads as well.. Its all a matter of getting the car to hook, and launch hard.
Cool  

19plymouth64 19plymouth64
New User | Posts: 3 | Joined: 01/13
Posted: 01/12/13
10:45 AM

The car launches pretty good with the drag radials and super stock springs. I usually see 1.9 60' times. It's the top end of the track where other cars start pulling on me. That xe274 looks like a good recommendation, do you think the the xe284 would be to much cam for my set up.  

drmopar drmopar
Guru | Posts: 1445 | Joined: 02/08
Posted: 01/12/13
11:05 AM

The 284 is the better cam but at the expense of torque, that is why I suggested the 274.I know they recommend converter stall in the 27-3700 range, however I find these recommendations to be soft when talking real world performance. Always try to get the converter flash in the cams max. torque range to get it up and moving quickly off the line. A good trade off would be to advance the 284 4 degrees to regain some of the torque losted at low RPM.. I have had good success with 4 hole spacers with the 360's to improve 60 ft times as well. Try a 1" and add one size larger jets in the rear of the carb.
Cool  

marcohotrod340 marcohotrod340
Enthusiast | Posts: 466 | Joined: 09/08
Posted: 01/20/13
09:38 AM

if you are gettin passed on the big end you need more top end power, and more off the line and midrange will help too. what is the car weight and what rpm at the finish line? go more gear, more cam, more comp. ratio, 750 carb, 1.75" headers, etc.