Thread: head casting numbers

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im gonna match the intake ports on the heads with the ones on my intake. with flat tops the CR calculator gave me somewhere around 9.3:1

9.3:1 with those 76 cc heads?

thats what it said

that would be ideal. wouldn't flow the best, but it should be ok. The deck must have been milled then. my pistons weren't flat tops, but they only had valve reliefs and my compression was 8.3:1

what was your deck heigth?

I don't remember, whatever came from the factory. I never had my block machined or anything. I don't know how responsive those heads are to porting and polishing but it you polish and take it easy with cutting tools you could probably improve them greatly. If you haven't had the block milled andyou are going to be gettign 9.3:1 with 76 cc heads I'd be afraid of going to a smaller chamber head.

the pistons im looking at says it will give me a 8.5:1 CR with my heads. assuming everything else is stock. theyre cast but i dont care, and theyre under 100 bucks

ok cool so you could get by with running a smaller chambered head eventually. I don't know what camshaft you should use if you want to make decent power with that low of compression. part of the reason I put on those 416's is because I didn't have the money for aftermarket heads and comp cams recommended a higher compression for my camshaft. You should be ok with those pistoins as long as you have reasonable expectations with what you want to do with it. I wouldn't recommend NOS or any power adder on them.

since basically it's a stock truck motor rebuild I guess I'd think about using a truck or rv cam. Make some good low end torque.

actually i should CC the little dish in the pistons i have now. it doesnt look very big

I have some 882s, too. They're good as door stoppers, boat anchors, sunshade-stands,... They flow quite well for such a small runner volume, but they don't give good compression and combustion characteristics. I just got two sets of 882s given to me, tried one, tore them off as soon as I had a replacement. If your pistons are OK, use them. If you're too low on money to afford one head, then don't bother about bottom end swaps unless something is broken or wobbly. If the short block is OK, go for some decent heads. You should be able to get some good heads (a pair) for under 200 bucks at a junk yard. If you get them with the same size valves as you have now you can even look for bare heads and rebuild them with your valves, springs, etc... Watch out with the springs, some castings will give you more or less installed height, but that shouldn't be an issue with "normal" springs. And check your cam is good for the CR. Changing heads is the easiest way to free up a bit of power and you can get some good heads at junk yards for little money. The price rises when you go from good to very good, not when you go from bad to good. Go for 041/186/492 style heads, or any closed chamber with 64-68 cc. I don't believe you'll get 9.3 static CR with 76cc heads. You'd either have to have the block milled by some or use domed pistons, both of which costs a lot and gets you nowhere in a DD. Much cheaper and easier to get decent heads, whack em on and have done with it. Later, when you have the money, you can drop in a really nice motor, look forward to that day
Hope I could help,
Mad

thanks man helped alot. actually i just bought a complete 350 out of a van. because i needed alot of stuff anyways and i have a set of standard bore dome pistons for it . ill see what kind of heads they have if theyre trash ill find a head,

Before spending any bucks on those 882's check the exhaust ports with a good light. I've had dozens of them, and at least half were cracked in one of the center two ports.

oh man 416's are a decent head with some slight chamber polishing and opening up the exhaust ports.......man all you nned to do is have them machined for 1.94 intake valves and you have a set of mini camel humps.....i have 2 sets that I have fully ported and polished one set has the 1.84 intakes that are on my 335" and the other set when I am done polishing will go in and have the 1.94 intakes installed......these are good heads, considering the cost of after market 58cc and 64cc heads its a real bargain to machine these. 882's are very thin and are prone to cracking between the two adjacent exhaust valves, the76cc chamber is pretty big andunless you are running a higher compression piston they will not perform that well. If on a budget, the 416's are your best bet, just be wise on camshaft selection.

I have untouched 416's on my 350 and it runs great seems to run out at upper rpm's. If I had the time and wasn't doing work along side of the street I would've taken the time to polish and do some work on them. Biggest thing that sucks to get the bigger valves you loose some compression.

you wont loose much more than maybe 1 cc.....there isnt a whole lot of difference between 1.84" and 1.94"