If I were to put new heads on my 283, what are my choices. I know that larger valve heads are out because the bores on my block are too smal. But what is the limit? Can I run 1.95 intake 1.5 exhaust double bumb heads? How about 1.85 intake 1.5 305 heads. I know powerpack heads will work, but what else? Thanks.
I don't have any part numbers in my head but you can probably find them at the mortec site. we normaly use 305 heads, or 307 heads. you can hawg the ports and make 'em breath just fine and they're cheap. Put any valve that will fit in the combustion chamber, but you will probably have to unshroud the intake if you go bigger than stock. you can also relieve the top of the cylinder on the 283 to make it work. Here's a treick you might try, instead of going bigger with the intake go bigger with the exhaust, even as far as matching the intake. you should have room to do that. remember a clean cylinder will make more zot than a dirty one.
I'm running World Products S/R 305 heads on a 262" SBC (Federal Monza engine) They have 1.94" intakes, 58cc chambers, and work on a smaller bore than the 283. They get away with it by spacing the valves closer together than stock (If you use them they need 4" bore headgaskets) Supposedly they have similar runners to a double hump head but with tapped "accessory" holes in the ends for long waterpump alternator, etc. mounting. They work for me.
There are some used 305 heads in my neck of the woods on E-Bay for cheep. They are 601 castings, which I have heard good things about. Anything I should be worried about if I want to use these heads?
Looks like I'm going to be using power pack heads. I found a matching pair with hardened exhaust valve seats for $60. They look good enough but have some surface rust on the springs and the mating surface of the heads. Can someone advise me on what sort of clean up I should do for the surface rust and such before I bolt these on?
I know a couple guys that have had good luck on power pack heads by opening up the intake seats and replacing the stock 1.72 intake valves with 1.84s from 305 heads.
Take 'em to the machine shop throw the guy a 20 and get 'em faced, the minimum that they will be straight at. Then bolt 'em on. Otherwise get yourself a sanding blobk and some 1500 grit wet or dry. getting 'em faced is your best bet.
$20 don't go far at a machine shop these days. How about using a big chunk of flat metal as a sanding block, and some 180 or so grit wet/dry paper....or a whetstone....and use some solvent too, such as mineral spirits or WD40. As long as the heads aren't warped, this will clean them up nice.
I'm putting double hump 2.02 heads on my 327! But, I know several guys that have switched to vortec heads - everyone that has switched loves those heads. There is only one drawback - there are next to 0 traditional/nostalgia intakes that fit vortec heads. Edelbrock makes a dual 4barrel intake and maybe a 3 deuce intake for vortecs. Check in the jegs catalog or online.
Ya, Ya, I know. But for a good set of heads I just could not beat $60, and I like the traditional look of the power pack heads, which look correct on my 283, which was manufactured the same year as the heads.
Ive done the same thing as mentioned above. Most SB heads will remain pretty flat as long as theyve not been overheated to the point of meltdown.A good straightedge & flashlight will show low spots if any,& if its minimal,the FP blue gaskets will seal fine. Watch out for the lightweight castings,,,,the ones with the scalloped edge right below the lower head bolt holes.They crack easy in the chamber area if overheated. Your choice. (Is this the beginning of a new tech week? )
What is a good way to check to see if they are warped? I took a metal angle ruler and used that to check them and they seem flat. Is this good enough? Also, should I replace the springs, or is there a way to test them to determine if I should replace them? I may go ahead and replace the intake valves, which appear original. The exhaust valves look new and were probably replaced when the hardened seats were put in. OK, one more thing, where the hardened seats where put into the exhaust sides there is a sharpe edge, they were not blended into the head...is this a problem...can I fix it myself if it is, or is this a machine shop job.
Ha Ha...I was just clownin' ya some!! With hardened valve seats and a clean-up on them heads, you should get what you're after from your motor. It's smart to build it to run on TODAY'S fuel...but for many, who don't drive but maybe a couple hundred miles per year, it doesn't matter so much I guess. You deffinitely got a deal!!
When the seats were installed, the heads got a valve job too, so I'd leave the intake valves alone. The springs might be iffy....if they have thick shims under them then they are probably getting weak and should be replaced. I wouldn't mess with trying to blend the seats unless you're prepared to pay for another valve job....
Thanks. I suspect I got a good deal because this guy was not selling parts at the swap meet. He had a bunch of new bug shields for trucks and mirrors etc. No old parts, except for these heads, which it turns out did not work on his 350 so well.....I'm just learning my way into the old car hobby but I was sure I knew just a bit more about what goes with what than this guy did and that is all it takes some times.
Thanks! I can see shims under a number of them. Guess I'll buy a spring compressor and take them off and determine how thick the shims are.
Check! I'm guessing that new springs will need to be at the same installed height as the old?....or at least all the same, right? Obviously I've never messed with heads befor. Sorry if my questions sound stupid.
As cheap as small block valve springs are, buy a set. What sort of valve lift are you running? Stock 283 springs sign off around .450, less if they're shimmed heavily.
The deal with the installed height, and shims, is that when you do a valve job usually the distance between the retainer and the head increases, so you need to add some shim to make up for it. But also as springs age, they exert less pressure, so you can shim them more to make up for it. So you need to see what the actual installed height of the springs is....if they are shorter than spec, that means the springs were shimmed to make up for being weak. If they are at spec height, then they might have been ok. If you have some experience looking at springs you migth be able to tell if they've been replaced recently. If they're old, then you ought to replace them...if they're not very old, then they should be ok. If you can't tell, then you should replace them anyways to be sure.
I'm right there with you. Went out the the garage just to look at em' three times the night I bought them.
Getting back to the original question, I installed 1.94s in my powerpac heads. Of course the chambers had to be unshrouded. Hardened seats both sides, screw-in studs, stainless valves, new guides, springs, etc. The original heads the block was born with(to a '66 Nova), original water pump, distributor, crank and rods(balanced), new 060-over pistons(makes it a 292), Comp 268 kit, 15-lb flywheel, Performer RPM intake with Holley 450. Lugs from a stop like Granny's car and then makes that delicious 283 chevy howl as you scream past 4,000 with what feels like the G-forces of the space shuttle. SBC bashers can kiss my ass when they catch up.
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