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Peanut Port Heads? PLZ HELP


Robs71Nova
07-11-2004, 02:40 PM
Hello all. I recently acquired a 454 to drop in my Nova. I pulled the 454 out a running '86 suburban with 80k original miles, and I paid 325 for the complete motor, minus the carb (yes it was carbuerated). As of now I have the motor COMPLETELY tore down, with just the block sitting on an engine stand. The pistons and rods are in excellent shape, so I put a new set of rings on the pistons and will be using the same pistons/rods that came out of it. Here is my question: Is there any way to look at the heads and tell if they are the "Peanut port" heads that chevy put on their big block trucks? I ran the numbers on the heads, but I cant find much information on them. The only thing it says is "open chambered oval ports" I am really hoping that the heads are NOT peanut port heads, because these type of heads make awsome torque/low end power, but dont run worth anything on the top end. I really dont think they are Peanut ports because the heads are open chambered, and the block is marked "HP" in two different spots, and is marked "Hi Perf" on the back by the casting numbers, and I really dont think they would put peanut ports on a high performance block. I am just tyring to find out for sure. I had planned on getting the heads shaved, cut for bigger valves, etc, but if they are peanut port I am going to be looking for a new set. Any info would be appreciated.
Thanks

Rob

slothboy
07-15-2004, 03:00 AM
Peanut Ports Generally Came In Foreign Motors Ex.datsun. Peanut Ports Are A Closed Chamber. If You Look At Them There In The Shape Of A Peanut(more Like A Kidney Bean)it Was A Sm.conbustion Chamber 1.5" Its Doubtful That Its A Peanut Port!

MrPbody
07-23-2004, 08:22 AM
The "good" oval ports measure about 1.93" in height, and 1.67" in width. The chamber is nearly a triangle shape. The early 454 heads have a larger chamber, with a flat area behind the exhaust valve.
If your intake ports are significantly shorter than the above dimension, you have what are called "peanut" heads. In reality, they're "fuel injected" heads. And yes, they were installed on some carbureted models. Your information about torque and low-speed power is accurate.
The best of the oval ports are from '68 and '69 396s and 427s. '67 and earlier BB heads are "closed chamber" All '68 and newer except 366 have "open" chambers. But as previously stated, there are variations on the theme. I have one pair in the shop right now, with the "good" ports, casting number 781 (last 3 digits). They have the good chamber and large ports. But the casting date says 1-1-73. I have no idea what vehicle they were originally installed in. Probably a Corvette or Chevelle SS. All the truck heads with larger ports I've ever seen (MANY over the years) from '70 on, have had the ugly chamber.
You will find installing the 2.190 intake and 1.88 exhaust valves from the rectangular port heads will really wake it up on the high end. Some judicious porting on the intake side will help, too. The exhaust ports are already a little "too" efficient (sounds funny, but true), so no porting and only minor polishing are recommended.

redneck racer
02-27-2007, 05:22 PM
don't be fooled by missled answers from people, the peanut heads are a great street/strip head. they flow well all the way up to 0.700" lift, there smaller ports give great eff. and response. i am building a budget 454 at the moment and am using the 236 peanut heads and the motor is going to be around 550 to 560 HP and have 580+ torque. the best peanut heads to get are from the mid to late 70's

MagicRat
02-27-2007, 09:18 PM
Fine advice, racer, but it's two and a half years late.
Please do not resurrect ancient threads, it only annoys people who saw the thread back then.

Thread closed.

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