a friend of our pointed out that we had "powerpacked heads" in our 66 c10. its a 283 small block and he said he could tell by a small triangle on the front of the heads. what does this mean? and how do we nkow if its true? thanks.
pretty low tech stuff but true better yet is the double camel hump heads, also terribly obsolete think 1957 to 1963 era what was the horsepower??? maybee 280 with 2 4 barrels and look at what we get for heads nowdays 2.05 intakes big ports and proabbly no bottom end tork the old heads will do good for mostly stock street engines a lot of tork and not a ton of brute HP just my humble opinions
Small triangle on top of the a rectangle on front of heads is indeed a Powerpack head. They'll also have no accessory holes I believe. They are a head that accompanied a 4bbl engine which would signify a Horse Power minded head as compared to the economy heads of the year.
Yep, exactly. The base two barrel heads just had the rectangle on the ends while the 4 barrel (power pack) heads had the triangle on top of the rectangle. A bit better breathing and bigger valves than the two barrel heads. The work great on 307's too with a mid 80's Z28 cam and four barrel to go with them.
The Power Pack 283 4-barrel heads have a smaller combustion chamber than the 2-barrel heads for a higher compression ratio. The 2-barrel heads have a 64cc chamber for 8.5:1 compression, the Power Pack heads are 58cc for 9.5:1 compression. Same 1.72" intake and 1.50" exhaust valve sizes for both 2-barrel and Power Pack heads, ports are essentially the same too, the Power Pack heads don't have bigger valves. The Power Pack heads are just a higher compression variant of the standard 2-barrel heads, nothing more. The higher compression along with a 4-barrel carb and dual exhaust made the added power (220 HP) over the lower-compression 2-barrel engine with a single exhaust (185 HP).
520 was the magic number for the last 283 "stocker" we messed with. that and using a rochester base 327 intake was worth about a tenth , over the stock 220hp intake.....
In '66 both the 2-barrel (now 195 HP) and the 4-barrel (220 HP) versions were offered, 2-barrel heads were not Power Pack 9.5:1 heads. 1967 was the last year of the 283, only the low-compression 195 HP 2-barrel version was offered so there were no Power Pack heads on that one.
From the very first year the 1955 265 was offered in a 'Power Pack' version with higher compression heads, a 4-barrel and dual exhaust for 195 HP compared to the 162 HP 2-barrel single-exhaust version. Of course 1957 would have been the first year of the 220 HP Power Pack 283 since that was the year the Chevy V8 was first 'bored out' to 283 cubes.
take them and have 2.02 valves put in them,shave them a little and port the intake and exhaust.Sure aluminum heads are cheaper.I'm putting a set on the 383 I'm building.
They are already small chamber, so dont shave them, and They had 1.72's originally so i dont think there is meat, in the old days they put chev 6 with Powerglide 1.87 valves in. 305 1.84's are supposed to almost drop in, but i was quoted a grand last week for putting them in, anyone know what a good price is??
1967 was the last year of the 283, only the low-compression 195 HP 2-barrel version was offered so there were no Power Pack heads on that one.[/QUOTE] I don't know about no power heads on the 67 283. I have a virgin 2 barrel 283 out of a 67 nova that came with a power glide. and it has the power pack heads?
I had a set of 520 casting Power Pack heads converted to the 1.84" Chevy 305 intake valves, it sure didn't cost anywhere near a grand to have that part of the work done. Total for doing all the head work was close to $800. That included converting to screw-in studs, hardened exhaust valve seats, resurfacing, crack checking, hot tanking, new bronze guides, pretty much enough machine work and new parts to do them right.
Please don't confuse the High performance 327 double hump heads with the earlier Power Pack heads. They are two completely different animals. It seems that many people like to call all high performance Chevy heads "Power Pack" heads. That is not accurate. We usually referred to the later 327 heads by the HP of the Corvette engine that they came on back then...340hp heads, 365hp heads or 375hp heads. Even though the 365 and 375 heads were the same. Nobody that I knew called 327 heads power pack. That's like fingernails on a chalk board to me. The only people that wanted the power pack heads in the middle sixties were the restorers. We all wanted the 365 heads.
All '64 through '66 passenger car 283's, whether 2 or 4 bbl., were 9.25 to 1 and came with Power Pak heads. The only difference was the intake and the 4 bbl. cars got dual exhaust. Can't say on the '67 283's because I never had one but I know that some late '63 283 2 bbls. came with Power Pak heads, had one. Trucks had lower compression and used the large chamber heads. Power Pak heads also came on the '62-'64 250HP 327's.
The 270 hp heads have a casting number ending in 997. When you go looking for them, take lots of money with you.
i can buy a 283 engine with powerpack heads for around 300 bucks it needs a rebuild. i dont have a car for it so it wil end up waiting. i thought could be pretty cool for a hotrod project. add a tri power setup. headers dual exhaust system it wont fly but could be pretty cool though, dont know if they are cheap to build. the tripower setup aint the problem got that laying around. just the engine rebuild. i havent seen it in person yet so im not sure about the state of it. so what do you guys think ?
283 is going to cost a little bit more than the newer 350 or 305 for example. Mostly because of popularity brings part costs down. So 283 pistons and rings cost more. The small journal bearings are a bit higher. Machine work is essentially the same. Cam and timing chain are same costs. Dedicated 283 gasket set with the smaller head gasket size will be higher than universal 4-inch bore HG. The PP heads are nothing special, but nice for a traditional build. Completely going through the old heads will cost more than new replacements like Vortec's for example. 283 are a great little engine, the short stroke is great for rpms. Works best in a lighter car just because less low end.
1957 283 was the first production motor to hit 1Hp per cubic inch. In my book that puts it pretty far up there in terms of importance.
They wont accept 2.02" valves without chamber work, and then you lost the small 58cc chambers, and will have 64cc chambers after relieving for larger valves. But they can be done. If you look at all the older 2.02" camel hump heads you'll see the chamber is machined for clearance and flow. A 1.94 valve would work on a stock 283, and fit the chamber, so could go to those and be OK. $1,000 to put in larger valves is nuts! My local machine shop will take old SBC heads and put in hardened seats, new larger SS valves, new seals, and do the whole job for $400. A little more if the heads need new guides also.
thanks for the info really helped me decide. ill let this one ride the waves and move on. still i learned a few things thats Always nice.i got lots of other ideas and projects to put money in so it wont get wasted