just swapped in a 65 SS 327 in my 49 chevy has the #870 block.has 3795896 casting heads can these heads be built up and make some good power.and can these take 1.94's .because these heads originaly had 1.72 intake valves.never tinkered with these style of heads before.
Personally I'd look around for something else, i/e that already has 1.94 or 2.02 intake valve, like 461's, etc....I think it'll save you some dollars in the long run (***uming the valves are good in the heads you get) instead of recutting seats, and buying new valves.
Thety're good head, most are 62cc's, have good flow characteristics, and can be ported to flow better...problem is, unless you can do all the porting/etc, yourself, there are many aftermarket iron heads that you can just bolt on and run, an out perform the older "Double Humps". Back "in the day" they were the choice of SBC racers/hotrodders.
These are original PowerPak heads. They make good power, have a ton of iron in them, so they can be ported any way you want. The throats are thick enough to take hardened seats and to go to 1.94 easily on the intake and 1.60 on the exhaust. 2.02 will shroud unless they are relieved. They almost never crack and can stand a LOT of pressure and heat. They used to be remodeled into blower heads for 283's and 327's a lot. They do not have accessorie holes up front so are very clean if looking for old school.
thanks for the info. in a couple of months will take them off and put bigger valves and port them and drop in a good cam.should move decent
While they wont hit the block the valves are still shrouded even on a 400 block. Just my opinion. Pete
_______________________________________________________________ It's not that they are bad, just to start making power, you'd have to invest too much money into them and they would get out performed with today's out of the box aftermarket heads for less of an investment.
i understand that i can buy new heads out of the box but rather run early heads or work with what i got.also not plan on making tons of power just want to keep up
The shrouding that is talked about is in the combuston chamber not the cylinder of the block. The small chamber heads will shroud 1.94's some and 2.02 a little more. If you do not need the small chamber for compression reasons I'd do some chamber work on them just to unshroud the valves. No matter what it will help and increase flow. Even the bigger chamber heads can benefit from chamber work.
Yeah, I was talking about the sides of the chamber shrouding the valves. These old heads are a great place to start learning port work with a die grinder and some carbide bits. They can be worked many ways. They're just a good place to start learning the tricks and what works
alright have another question wanted to see what my motor excatly came out of so and hp rating i go and try to look st the suffix codes and no numbers i dont think it was rebuilt and decked motor was untouched since 65?so i was told.anyhow i saw a number behind the distributor and say ...015... what does that mean was told it came out of a 65 imp ss.but want more info
Can't help on the numbers, but if it is in fact a 65 327 with Powerpak heads it was rated at 250hp. It would have had a small 4bbl and dual exhausts. The 300 hp 327 had the double hump heads, an AFB, and the 2 1/2" rams horns. I think they both had the 929 cam.
If engine block has not been decked check pad in front of cylinder head to get the numbers you need to check what it is out of.
i did look at this stamp pad and there is nothing doesnt even looked machined also it has a 4brl large base manifold for a carter.049 casting .could this been a replacement engine? also it did have ram horns with the 2 1/2 outlets but are using log manifolds now because its in my 49 chevy
1964 was the last year they used the PowerPak heads on p***enger car 327's. In '65 they switched the 250HP 327's to the 461 heads the same as the 300HP but kept the small 4GC/WCFB intake manifold. The 300HP got the AFB intake and in '66 some of them got the one year only Holley/AVS cast iron intake. '64 was the last year I have seen the 2-1/2" manifolds on an Impala and they were never used on the 250HP, neither was the large base 4 bbl. intake. Sounds like the '65 had an engine replaced somewhere along the line or somebody did some parts swapping which was REAL common. The '65 283/220HP 4 Bbl. also used Power Pak heads.......... According to Mortec your heads were used on '62-'64 327's and '63-'65 283's.
Unless your going to be doing some high RPM racing you dont really need 2.02 heads. 1.94 are just fine. You"ll lose some low end torque with the 2.02 heads. With the money your going to spend on building those heads up you can get a new set of vortech heads right from any G.M dealer. Jim Pace chevrolet sells them for $450 a pair brand new. Best flowing steel heads on the market. They just wont take alot of cam without machine work and better valve springs. Yopu also gotta buy the intake because older style wont fit.
dont want vortech heads or aftermarket using what i have and get my machine work done for cheap as a mater of fact already have a xtra set of 869 power packs that will be ported and polished and using bigger valves and what not.thanks
Yup. If it was me I'd put hardened exhaust seats in the PowerPaks and 1.84 valves from a 305, do some pocket porting and run 'em. A friend of mine has a mint '64 Impala SS with a 327/250HP; 200-4R and 3.73 posi. He's running the original shortblock, the PowerPak heads have been mildly ported with the stock 1.72/1.50 valves and upgraded springs, a Summit 1103 cam, stock intake manifold with a rejetted 4GC, recurved stock point distributor and 2" ram horns. It "keeps up" and then some!
i have a weiand intake 600 carb and a cam for this motor the heads are going to have large valves. gasket matched using large port gaskets and port and polish and z/28 springs.not putting this set up until the heads are done oh will machine them for screw in studs and guide plates so i can run roller rockers.already have camaro 8.5 10 bolt with 3.73 posi installed in my chevy should do okay
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