350 heads on 327

[rockhop051]

Question for the engine guys: Can I pull the valves and springs off my 327 heads and put them into a set of 350 heads?

I want to keep the 327 because its in good shape but would like to have the bolt holes the 350 heads provide so I can use newer style alternator brackets.

Thanks

[blackedoutharley]

You can do that but you would need to regrind the valves to match the seats on the new heads (basically a valve job) assuming that the valves are the same size.

Also be aware that the later model 350 heads may have a larger combustion chamber (measured in cc's) which will lower the compression ratio.

The better way to do it is to purchase new valves and springs for the 350 heads and start fresh. Using used valves and springs doesn't sound like a good idea.

YMMV

[61_FL_Apache]

Go with new springs.

[Captainfab]

Be careful with changing to the 350 heads. As blackedoutharley said the larger combustion chambers in the typical 350 heads will drop your compression. In doing so your 327 will not run as good as it did before. I had a 327 once that the PO installed a set of 350 76cc heads on......what a turd. Bear in mind that there are some 350 heads that had smaller combustion chambers. The best 350 heads to switch to would be the Vortecs. Those would wake up your 327 and they would keep your compression where it is now. But then you would have to get a different intake manifold.

[TheDark1]

You will need to "CC" the head to determine the actual combustion chamber size. This will be easiest way to compare the head volume from each engine.

http://www.jrbranson.com/HondaRacer/...-CC-a-head.htm

This is one of the simplest ways to do it. It only needs to be done on one chamber from each head to reach a comparison. If they're the same volume, then the compression will be the same.
As far as using used valves and springs, that'll depend on the condition of the valves, springs, and seats themselves. Some people make a science and a good living out of just doing heads. You could easily spend more money on redoing an old set if you got into setting valve height, new springs, stainless valves, guide replacement etc. Especially when you consider the Vortecs like CaptainFab said. You could then pick your compression ratio and the cam specs to match. Head and cam specs were the easiest way for GM to make so many different power levels in a given engine family. Most of these engines used flat top pistons and could make from 180hp to over 300 with the same short block.

If the only reason is to get a new style alterantor bracket, then don't do it. You could easily lose some performance if you have some excess wear in the 350 guides. Besides, then it'll look like every other 350 in a truck. I like the way a 283/327 looks in these trucks.
If it has to be done, reuse the 350 valves in the guide that it came from, don't mix them up! Use the 327 springs and the caps and retainers from the 350 valves. This is if everything is stock. If you have "Beehive or MutiSpring" springs, then use the retainers and caps from them. Check for valve length also and make sure they're the same from the 327 and 350.
Dang!!! I'm a long winded SOB....Jeff

[rockhop051]

Thanks for all of that great info guys and I agree with "61 son" no such thing as longwinded on here.

After reading what everyone has to say I'm going to take thedark1's advice and keep the 327 heads. It is cool to say you have a 327 in your truck.

Now its off to the machine shop for a valve job.

Thanks again everyone.

[1Bad62Pro/Street]

Originally Posted by rockhop051

Thanks for all of that great info guys and I agree with "61 son" no such thing as longwinded on here.

After reading what everyone has to say I'm going to take thedark1's advice and keep the 327 heads. It is cool to say you have a 327 in your truck.

Now its off to the machine shop for a valve job.

Thanks again everyone.

Are those Camel Hump Heads?

The double hump or camel hump casting symbol
on the end of this head indicates a performance
cast-iron head used in the sixties. The lack of
accessory bolt holes in this head narrows the
possibilities as to which casting this is. Looking at
the head casting number revealed that it was a
“461” casting with 1.94"/1.5" valves that was
found on a 327/300hp motor.
Small Block Chevy Cylinder Head Identification
http://67-72chevytrucks.com/vboard/s...32#post4228732
Online engine resources (casting numbers, calculators, etc.)
http://67-72chevytrucks.com/vboard/s...d.php?t=382583

[TheDark1]

I have a set of those small camel hump heads in the attic. Just in case I ever decide to go to more vintage motor.

rockhop051...Let us know how the heads turn out.

[1Bad62Pro/Street]

That's what I have on my 355ci. Ole' Camel Hump heads..


Project: "Full Metal Yellow Jacket" Build Thread
http://67-72chevytrucks.com/vboard/s...d.php?t=321173

YouTube - Gotta fire the Ole' '62 up and...

[bama63]

other than the lack of accessory mounting holes there is one major consideration when using the early heads, all heads built before 1975 do not have hardened exhaust seats as they were designed for leaded fuel and if you intend to use this as a daily driver you would need to add a upper cylinder lubricant with every fill up to prevent seat wear and receding valves, otherwise as a limited use truck you will be ok without the additive and will be fine