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doublehumps, camelhumps, or aftermarket?

4K views 18 replies 14 participants last post by  bigjoedo 
#1 ·
i would like to put a good set of heads on my 350. i want a good street motor that makes 350-400 hp with lots of torque. will the gm heads above make this much power with 9.5 compression. they made immpressive hp back in the day but that was with higher compression engines, right? what are the valve sizes on the 2 gm heads and the combustion chamber sizes. thanks
 
#2 ·
using GM stock production heads for serious street horsepower is a waste of time and money, the camel backs are all over thirty years old, they all need so much work it costs as much as aftermarket heads and you still haven't the flow of an aftermarket SR type head. i see inexperienced people every week bring in camel back heads that they just got a real deal on ($300-400.00) then have to tell the valve guides are shot, the valve stems worn, springs gone, and to use modern fuels they have to have seats and stainless valves. don't try the reverse flow corvette heads either, someone has been stealing them from GM in this area and selling them to kids and people who don't know better. they try hose fittings in front to bypass water to the intake etc. it doesn't work,one guy brought his heads in to be milled three times before giving up on them, warped beyond belief.
 
#3 ·
I have a set of camel humps on a 9.5:1 406 in an 80 malibu with a solid flat tappet cam and it runs 11.80's on motor and 10.50's on a 175 shot.I agree that there are better heads out there,but I didnt need to do much to mine.I have the stock 1.94/1.50" valves that they came with,with a set of thread in liners,and a 3 angle valve job,and I blended the bowls.I did no other portwork.I also ran these heads for 5 years on my 73 camaro street car with no hardened sets and used unleaded pump gas.I pulled them apart to put in new springs when they went on the malibu and the valve job was fine.I relapped the valve and they are still running strong.They are factory screw in studs and guideplate heads that I got when I parted out a 83 powered V8 Vega that I bought for $400,so they cost me nothing{I sold the car without the engine for $1000.I wouldnt pay more the $100 for those heads,but they are out there for that price.I payed $150 to have them cleaned and the liners put in,and I finished the valvejob myself with a cheapie old stlye valve grinding setup.This engine replaced a roller cammed 355 with dart 2 heads and 11:1 that ran 12.0's,so it is obviously doing something right.
 
#5 ·
Camelhumps and double humps are the same thing its just slang for the little shape on the fronts.
My uncle had a 1980 Monza with a 12:1 331 with 2.02/1.60 double humps with stainless valves the car ran 6.3 in the eighth.
Its my personal belief that unless you wanna run in a serious competition class camel humps are still the best.But it is getting tough to find um in decent shape.Although I seen fully preped ready to run 2.02s for $600 at Carlisle.
 
#6 ·
everyone told me they were different heads shows what they know. well since the gm heads are hard to find and i would have to have them rebuilt and then to get them to run good have them ported and bowl job. that would probably cost the same as a good set of aftermarket heads. so would the S/R Torquers give me the power i'm wanting. in summit it says they make 30 horses over stock.
 
#7 ·
Well, if you trip over a set of camel humps, certainly go for it. However, remember there are several versions of the camel hump and some of them don't have accessary holes...bad in a newer autos' (about 70 and up)! I found a good set for 50 bucks (186s). I home ported them (great fun, really),had hardned seats installed, valve guides and stainess valves installed. I've got a little less than 500 bucks in those heads. They are still sitting on my shelf but I plan on installing them on my 400sb with slight dished forged pistons. I'm betting that it makes a solid 400 horse power on middle grade gas and has great street torque! Slip that motor in a mundane, dime a dozen, 80s cutlass with 3.73s and the stock over drive (Chevy engines will bolt up to Olds overdrives)and you have an instant "Yuppie mobile" killer! If you're a bit carefull, I bet you can get the auto and build up the motor for it, for very little, if any, over 3000 bucks! Start saving your pennys!
 
#8 ·
There is a little difference in the "humps" the later 186 style head had two very small half circles or "humps" at the very bottom of the head. The early 461 style head had a raised casting mark with two humps that resembles a camel's back. I think this is where the two terms double hump, and camel hump came from.
Anyway, there are alot of good double hump heads still around, but you have to know something about automotive machining to separate the wheat from the chaff. You need to watch for cracks, excessive seat grinding {sunken valves} and worn valve guides. I saw a set of 186 heads with 2.02 intakes, and 1.6 exhaust with screw in studs and guide plates that looked to be in very good shape, go for 200.00. The combustion chamber on these heads is very condusive to good horsepower, especially with a little port work.
However, other guys are right in saying the SR head is a better deal, because it's ready to go.
I think the SR heads are well over $550.00 or more a pair. If you can pick up some good double hump heads for 150.00, you are still going to probably spend at least 300.00 more at the machine shop. {Also be wary of amateur port jobs, as alot of the time the port work is crappy, and makes the heads flow worse.}T
 
#9 ·
thats was my biggest concern that i would have to have them ported, and i don't know where to go to have this done. so i guess i will go with the S/R torquers even though they are a little more expensive. are there any cast iron heads that are better than the S/R Torquers for a strong street motor.
 
#10 ·
Hey 84Camaro.
Go to www.enginekits.com, scroll to the bottom and check out the pro lightning heads! 675 bucks, fully assembled with 180 or 200cc intake runners, 2.02 or 2.08X1.60 valves, guides and all. Id say those flow good. HG
 
#11 ·
This is a little info that sent me after some of these heads, and I like them a lot. Mine have been machined to accept a .600" lift and have new springs. I used an Edelbrock Vortec Performer RPM manifold and a 600cfm square bore carb.

This is from MorTec.com's "notes" page..


If you are thinking about rebuilding a set of old "camelhump" heads or using a set of 1960's or 70's vintage cast iron production heads, check this out first. The '96 and later smallblock "Vortec" 350 cast iron heads are a very hot item. These "L31" heads with casting number 10239906 and 12558062 or PN-12529093 (bare), flow great numbers for a production head, even better than the Phase 2 Bowtie cast iron head, when fitted with 2.02/1.60" valves and bowl ported. The complete heads (PN-12558060) come with 1.94"/1.5" valves and pressed in rocker studs, but can easily be fitted with 2.02"/1.6" valves and screw in studs. Chamber volumes are 64cc and intake port volumes are 170cc. The Vortec heads have raised intake ports and "fast burn" chambers. The heads require the use of narrow body "self-aligning" rocker arms and center bolt valve covers. They will bolt to any Gen.1 block.

The price per pair for new complete Vortec "L31"heads (PN-12558060) is about $425.00 (as of 10/1/01), with 1.94"/1.5" valves, springs and retainers from GM/Performance Parts. You can then use the valve sizes you want to use and drill and tap for screw in studs. However, the intake manifold bolt holes are in different locations than previous Gen.1 heads. Only four intake bolts are used on each side to fit the "Vortec" style intake, instead of the usual six on each side. The correct Vortec intake manifold bolts are found under PN-12550027. Use Vortec intake gasket PN-12529094. The stock Vortec L31 valve springs are good for lifts up to .475"-.480" maximum. If you use a cam with more lift you'll need to change the springs and have the valve guides machined down to clear seals and retainers.

You can redrill and tap the heads to fit the older style Gen.1 intakes, but why bother, Edelbrock has aluminum two and four barrel "Vortec" style intakes out that have the correct bolt hole positions. Edelbrock PN-7116 is their "Performer RPM", dual plane, high rise intake for the "Vortec" heads, while Edelbrock PN-2116 is their "Performer" street dual plane for 4-barrels. They also have two "Vortec" versions of the new "Super Victor" aluminum, high rise, open plenum race manifolds. PN-2912 is for 2-barrel restricted class racers and PN-2913 fits a 4-barrel intake to the "Vortec" RPO "L-31" heads. Vortec style intakes are also available for TBI and TPI setups.

GM/Performance Parts has a dual plane aluminum four barrel intake that is PN-12366573 and fits the unique Vortec intake manifold bolt pattern. GM also has a aluminum open plenum high rise (PN-12496822) intake for the Vortec L31 heads.
 
#12 ·
well i know i am going aftermarket, but now have to decide on which ones. yea i've read good things about vortecs but i already have performer rpm intake, and edelbrock valve covers. HG them pro lightning heads do sound good 2.05 int. valves 180cc runners, sounds like it would be good street heads price ain't too bad neither. does anybody have these heads or other aftermarket cast iron heads.
 
#14 ·
I have a set of 461's on a 400 sbc, and they make very good power. They have been bowl ported also. I did spend way too much money on them though, and would not do it again unless I got a cheap set. It cost me $650 by the time I got all the parts and machine work done.

I also recently read an article where the camel humps made more power than the S/R torqers. Can remember the magazine, but they lost about 20 HP on a mild 350 with the torqers. Turns out the larger ports killed port velocity and the small cam did not allow the motor to rev high enough to get the top end power.

Remember, bigger is not always better.

Chris
 
#16 ·
im 19 years old and havent been doing this for 20 years like some have . i have only built 2 engines and both run great. on the engine that i built for myself i put a set of 462 heads. port and bowl work done screw in studs guide plates milled to accept heavier springs 194in 160ex. for 200 bucks cant beat that. i have had nothing but praise with these heads. but not every one can find a steal. i was thinking of goning to engine kits.com for those heads, if you get them let me know how they turn out :D
 
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