View Full Version : 416 heads on a 350??


crailbait
03-19-2006, 11:19:02 PM
I was wondering if anyone has ever used casting # 416 heads (58cc 1.84/1.5) on a 350 engine? What are the pros and cons of using such heads? Lets just say the engine is bored 30 over...Thanks!

Jeff C.

CorkyE
03-19-2006, 11:46:02 PM
According to http://www.mortec.com/ these are - 14014416...80-86...305..........1.84"/1.5" valves, 58cc chambers. Most people tend to shy away from 305 heads for a couple of reasons. One is the 58cc chamber which is going to raise the compression ratio considerably and the small valves and runners which will run out of breath pretty quick. Some are proponents of these little heads, I'm not. If they are in good shape, ie; you don't have to spend any money on them for a rebuild and you are on a very tight budget, put some thick head gaskets on and use them. If you can afford something else, don't even consider the 416's. IMHO

crailbait
03-19-2006, 11:53:32 PM
I have a 305 in the car right now and bought the heads for the 305 as an upgrade. They are completely redone and ready to bolt on. i just found/bought a 350 engine for my car which matches up for my 71 Camaro. FYI - I bought the car with the 305 in it already. I didnt find out until later it was a 305..Guy that sold me the car stated it was a 350.) But anyways, i found the right engine and since i have the heads was wondering if i could use those to save on some money?? How thick of a gasket should i use i do decide to use them? How high of a compression ratio could i expect??

Jeff C.

Mwilson
03-20-2006, 05:00:18 AM
If its a typical Flattop piston with .025 in the hole, -6cc valve reliefs youd be at 11.02:1 with a .015 gasket. What cam converter gear you plan to use? A .039 will give you bad quench but put you at 10.32:1

1978LT
03-20-2006, 07:33:37 AM
The 416 heads make for a torquey 350! Ask PDQ67, he loves them.

classicz28
03-20-2006, 09:54:21 AM
I did the other stupid thing... Put 350 76cc heads on a 305. Almost no compression and no power. Ran ok though...just no power....

pdq67
03-20-2006, 10:16:28 AM
The -416's are more smog shaped likw W/P's Torquers whereas the -601's are double-quenched and shaped a whole lot like the old -461 double-hump fuelie heads!

Both good heads, but I lean towards the -601's.

And cc them regardless so you know exactly how big their chambers are!!

They both should have about 160 cc intake ports!! (At least my -601's do along with 53 to 55 cc chambers.)...

Great heads for the smaller motors, imho.. I think the roundy-round guys put an 1/8" to a 1/4" bullnose around the chamber outlines to open them up some for 350 motor use. It also makes them flow some better too.

pdq67

1978LT
03-20-2006, 01:03:47 PM
Also, we built a 350 with -434 305 heads, and it would totally roast the tires with the 1.72/1.45 valves!

1978LT
03-20-2006, 01:07:28 PM
I did the other stupid thing... Put 350 76cc heads on a 305. Almost no compression and no power. Ran ok though...just no power....

That's the first stupid car thing I did also!! Had like 120 psi cranking pressure!! That equals about 6.0 or 7.0 compression. :crazy: :eek:

caribbean camaro
03-20-2006, 04:53:59 PM
Crailbait - I am in the same boat as you - my 85 camaro original 305 was my first venture into hot rodding

I did the heads over with new springs, seals, a valve grind job, long slot rockers, 214/224 443./.465 cam - 114 lobe- flattop pistons

I soon got the bug and found that the 305 was just not cutting it & pulled the motor for my current 355ci

Now I am building up a budget hot street 350 .030 over for another car - and with all the goodies on the 305 heads- I plan to use them

MWILSON however has raised some issues for me -

"If its a typical Flattop piston with .025 in the hole, -6cc valve reliefs
youd be at 11.02:1 with a .015 gasket."

Are you sure that all I would need is H345NP flatop pistons (which I have) assuming a stock .025 in the hole to be near to 11:1 ???? I already have the 0.15 shim Fel Pro gaskets

Not doubting you MWILSON - but I have found that in practical terms - when you are just assembling parts as in budget builds - these assumptions about increasing compression don't always play out the way they are supposed to on paper - mainly because of all the variations in stock blocks and heads -

I was actually planning to use a set of used L2304 - .100" pop up pistons to ensure that I do not miss the near 11:1 mark for the 214/224 cam I plan to use

I personally think the 305 head on a .030 block will be a good street motor - and I intend to pursue it - as long as I can figure out if the compression will be up to snuff for my cam

Mwilson
03-20-2006, 06:13:02 PM
MWILSON however has raised some issues for me -

"If its a typical Flattop piston with .025 in the hole, -6cc valve reliefs
youd be at 11.02:1 with a .015 gasket."

Are you sure that all I would need is H345NP flatop pistons (which I have) assuming a stock .025 in the hole to be near to 11:1 ???? I already have the 0.15 shim Fel Pro gaskets

Not doubting you MWILSON - but I have found that in practical terms - when you are just assembling parts as in budget builds - these assumptions about increasing compression don't always play out the way they are supposed to on paper - mainly because of all the variations in stock blocks and heads -

I was actually planning to use a set of used L2304 - .100" pop up pistons to ensure that I do not miss the near 11:1 mark for the 214/224 cam I plan to use

I personally think the 305 head on a .030 block will be a good street motor - and I intend to pursue it - as long as I can figure out if the compression will be up to snuff for my cam

Those figures are with -6cc reliefs .025 in, 58cc chamber, .015 gasket


a typical .100 dome is gonna be about +1.3cc after you deduct for relief which would put you at 12.14:1

I do not believe the 214/224 would be a pump gas freindly cam with that compression. You need to get all the specs on that cam and check your dynamic compression ratio shoot for less than 9.0

pdq67
03-20-2006, 09:04:09 PM
The .020" over 283 engine I finally ended up with that was my air-head Nephew's had a good set of big valve -291's on it along with 4-notch flat-tops and .039" or so composite headgaskets! It was like 8 to 1 CR!!

UNKNOWINGLY built that way by non-motor guys!!

It also had a TRW 308/246, .433" lift hy-cam in it!!

DCR was right at 5.2!!

Sucker ran fine up top, but wouldn't pull me off my "Throne"!!

I figure this is why he ended up with it b/c he knows less about motors than the guys that built it!!

Bad, bad, bad!!

Anyway, after I get done with it, it will be about 10 to 1 and with my 280/246 solid cam, I will shift it above 8,000 rpm!

pdq67

Air_Adam
03-20-2006, 09:17:27 PM
Great heads for a warm 350, and even better with 1.94/1.50 or 1.60 valves. Its actually a very common thing to do for those with 3rdgen F-bodies, since all the pre-87 305s used those heads. They work great! I'll be using some done up 601 castings (very similar to 416 castings, but 53cc chambers) on my 350... they are great for production line GM heads!

crailbait
03-20-2006, 11:37:40 PM
Lets say i do decide to run the heads on the 350 engine being bored 30 over. What are your suggestions on what pistons to use and cam selection. I dont want anything wild here. Just looking to get maybe 350 horses. Is it possible.
I just want to run an edelbrock 600 CFM, edelbrock rpm air gap, those 416 heads. Do you think with the right cam i can get that 350 HP? Thanks for all your help guys!

Jeff C.

Ceth
03-21-2006, 12:48:08 AM
I dont think the heads flow enough in a high rpm to use the rpm air gap or to get 350hp, am I right? Ah cool youre in fullerton though, whats up? Im in HB.

crailbait
03-21-2006, 01:01:11 AM
Hey Ceth. Thanks for the advice...Yeah im right up the way....Are there any good cruise night spots around your area? The cops down there dont give ya any trouble with your car? I know they ticket for anything down there..

Jeff C.

Mwilson
03-21-2006, 06:29:39 AM
I dont think you'll have any problems getting 350hp out of it with that much compression Its gonna make power it may be maxed out at 5200 though just depends on the entire combo. Its gonna be torquey