Root is right they will drop your compression ratio...but also the larger valve will hit the cylinder wall unless you relieve it
i have only actually seen 3 pair of the 461x heads, and of those 3, only one had not been ported to hell...the best I could find was that the intake runner was a tad bit larger maybe 170-175 instead of the usual 160...and the x came directly after the casting number, not some where else on the head. I have guys try to sell me 461's that are supposed to be the x version because thay have an x on the head somewhere else. these all had 461X
Lots of great info here.........I think I need an asprin.........Thanks Fred, I have a line on a set of head this weekend and I will check out your specs. on them....... Chris Nelson Kansas
Racefab thanks for the article. It's better than any magazine I've picked up lately. I have a couple questions if you don't mind. 1) Over the years, I've seen heads with humps and with triangles. Singles and doubles. Are they the same or is there a secret code there somewhere? 2) These heads you show, are they for early model V-8s without the mounting holes or for the later model heads. I have a 77 model 350 4 bolt main block I need a good set of heads for and was wondering if these will work. I prefer the mounting holes. 3) How much performance gain will I see with these heads over the 1.94's for a street driven model A. Thanks again, and I appreciate any input you may offer.
Not hard to find at all. Just call Repoman. I have dozens of these. I have a for-sale ad in the classifieds. Mostly cores. This week I'll start picking out the best and posting ads one at a time for sets. I'll start with the ready-to-run heads.
The bracket holes became standard on the 1969 models, when they went to the long water pump. Some (very few) earlier heads had them....I have a pair of stagger bolt powerpacks with the holes! A triangle is a power pack head, small ports, small valves (1.72/1.50), closed chamber heads. Double humps are the big valve, big port, closed chamber heads.
Racefab, Awesome tech!!! Any guidance on prices? I know alot depends on condition and whats been done to it etc. They show up in the classifieds in Hawaii every now and again. The latest was with 202's for $500. I have spent way too much for parts before mostly because of my lack of knowledge -which is basically lack of bargaining power. Any advice on what to look for and ballpark prices? By the way thank you for your posts! aloha, rustfarmer
basically the edge of the valve is extremley close to the combustion chamber wall, the intake charge is restricted and cannot flow around the head of the valve. by machining the combustion chamber wall away from the valve .,..you open up some area for the intake charge to flow...this is a VERY basic explanation here you can see the shiny area where the chamber wall has been machined away
many e mails on the difference between the 461 and the 462 the 461 was the original camel hump, it had a spark plug location very close to the edge of the combustion chamber....also the combustion chamber had a little different shape than the D shape of the 462 the 462 and pretty much all the following camel hump heads had the D shaped chamber, and the spark plug location was moved with a large quench pad adjacent to it....these are the heads to use if you are going to run domed pistons, the 461's usually have some interference with domes and spark plugs. 461 462
Excellent, excellent post! For someone who has a beginners edge on sbc heads (me), you have helped me understand things in a very straight forward way. Use of pictures, two thumbs up!! Thanks for the info.
if you machine out the same amount you will keep the chamber sizes even...you could do it with a rotary file ....but I woud keep checking the combustion chamber volume and try to keep everything even...or as close as possible Fred
I have a 3 different sets of these heads, I keep hearing about a ghost....... 461-X head, is ther any truth to this #, I am negociating with someone now who claims to have a set of these in storage...no harm in looking I suppose...any introspect would be welcome...
You can get "Lead Additive" at your local parts house, I know that Autozone has it for like $4 a can. Its in a red metal can with silver and black writing on it, lead additive is the actual name for it also(not STP, Lucas, Slick 50). Its located with all the gas additives. By the way double humps do rock...............my 2 cents
Like said in a previous post 461X heads flow a little more than the originals, they are also twice as hard to find these heads were only available from 60-63 and are 172cc intake runners with 62cc combustion chambers instead of the original 64cc. Another great factory head is the 041 or 041X, these are the exact same casting(intake runners and combustion chamber design) as your double humps but have a right angle triangle instead of the camel humps. The X means the same here that it flows better. Just my 2 cents...........
How did I miss this!!! Oh, I was out of town.....now I know why I tell my wife "I don't like to go on vacation!" Thanks, FAB, this is just what I wanted to know for my next build. The next project is going to have Chevy's best screamer in it.... ......too cool! ....I bought some books on building the SBC and SBC parts interchange books....this stuff, here, is golden in comparrison!
Doing some research since I just picked up a complete running 327. I'm digging this thread up since I have a couple of questions. The engine block decoded as a 1969 full size car 327. What size journals does it have? 2.3", 2.45" ? I also have the 462 Camel Hump heads with a J66 date code. Withouut pulling the heads, is there a way to tell if I have the 2.02 or 1.94 intake valves? Didn't the double humps with the 1.94 valves show up on the 300HP motors? Thanks
69 is large journal the camel hump 1.94 heads were most common...yeah, they were on the 300 hp motors as usual, you have to pull the heads to see what you really have, a lot has happened to many pairs of heads over the past 40 years
Great info RACEFAB! probably the most i've found on the net. thanks to google i guess for finding it. and now, the huge question that i can't find the answer for.... I plan on putting douple humps on a 350 im building for my 86 trans am. The heads do not have the accessory holes in them( i think they are from '64, #462 2.02 1.60). Now, how do I use these heads and still mount all of my accesories(excluding ac) in the factory setup? Ive found some brackets in jegs, but i'm not positive they will work as theyre descriptions are vague. Any ideas? I cant be the only one that has wanted to do this. Thanks!
Great post RACEFAB. I'm left with a question though. In referencing both the larger 2.02" intakes, and the larger runner area of the 461x, you've stated that they "flow better." This may confuse some folks into thinking that bigger is always better. In this case, bigger usually equates to a significant loss of port velocity throughout the majority of the powerband until the revs really get up high.
mmmm, havent seen this thread in a while, will have to go back and read thru, but I dont think I said that the 461x's "flowed" better... I think i said they have more runner volume....170 to 175 cc on the ones I have cc'd compared to the 160cc of the stock 461 I also touched on how a smaller 1.94 valve could actually outflow a shrouded 2.02
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