I had a friend on the look out for some 081 heads, like found on the 5.0 ho motors. He called me and said he had found a guy with a 5.0 ho motor but it was a marine engine, and asked if i was interested, he said the motor only had 57 hours on it, and the heads were in great condition.

I doubt since its a marine engine it will have an 081 head, or will it? What casting number should i be looking for from an HO motor?

Or is 081 the only good ho head


Also: I am wanting these to go on my 350 to replace my crappy 193's, will they be great for my street car? stock or would they need worked?

 

081 and 416 are the same, except that 416 uses the old style perimiter-bolt valve covers. The rest is exactly the same - ports, chambers, bolt patterns, etc etc.

601 heads are better than both IMO. They are cast somewhat beefier and have a better chamber design for a performance engine.

416 castings came in basically EVERYTHING with a 305 before 1987, 601 castings came on trucks and vans with 262 and 305 engines in the late '70s - mid '80s. 081 cam only on TPI 305s. They are the same as 416 except for the valve covers.

 

Not quite. 081's also had the '87-up center two intake mount bolts at 72 degrees vs. 90 degrees.

FWIW, 081's never went on "HO" engines in 3rd gens. The later Monte's might have had them, though.

 

.

 

Yes, that is the other difference. Forgot about that - thanks Five7.

 

The 081 is on the left, the 416 on the right. These pics were found here at tgo so I can't verify the accuracy. However, I checked more than these and its confirmed by other pics posted. "The same" may be a subjective term. These chambers do not look the same to me. Its my opinion that there is not much the same about these two heads and that misinformation has been repeated about them.

 

The one on the right looks like an 083 (L98 - 64cc) head, and not an 081.

 

Here's another pic posted by a member who identifies this as 081. Its wrapped in plastic but you can still see the squarish sparkplug boss protruding into the chamber which the 416 lacks.

 

Here's another pic posted by a member here. Also said to be 081.
https://www.thirdgen.org/forums/tpi/...ine-motor.html

 

well i went out there, and sure enough it is an 081 head. Should I throw them on the 350? or upgrade to a 1.94 exhaust valve first?

 

Chester, the one on the left and the two subsequent photos look just like the 416's I took off my LG4 in 2001. The one on the right looks more like my World heads (except for the little dimple).

offset, whether you bolt them on or put 1.94" intake valves in first depends upon your goals. They'll work as-is on a mild 350, but if you want more, only you can decide whether to do the install more than once.

 

remember, wrench time is not a problem for me, im just wanting to familiarize my self with v8s, i just did the carb swap and now i got these heads to make my 350 stouter and get rid of the 193's that are on there now.

I just want a fun street car with a little 'oomph '

i got a bare block on the side to get built, im just playing with stock parts right now. If my car will be faster to ditch the 193's and throw the 081's on my 350 without working them ill go ahead with it.

 

416 from this thread:
https://www.thirdgen.org/forums/tech...-416-pics.html


416 from this thread:
https://www.thirdgen.org/forums/tech...6-heads-w.html

 

Fascinating.

 

Actually, I have seen 416s with both types of chambers. Both the recessed spark plug and the protruding bulge. The early 416s cast in the early 80s were the old open design and the later 416s from the mid 80s had the protruding bulge.

 

I wondered about something along that line, but wasn't willing to step out on a limb over it.

The ones I was referring to were '86 (sold them for $75 several years ago). There is an '82 LG4 waiting to be removed from its engine bay in the garage as we speak. I'm losing coolant in Camaro #1, figure I'll be pulling the Worlds someday soon. If they're cracked (got really overheated once), then the decision is Vortecs, or do the DIY SA port job on the '82 416's - might make for an interesting comparison either way.

 

I have a pair of 1985 model 416s from a SS Monte Carlo L69. This is the chamber.



I still favor the 601s 53cc closed chambers though, especially when they were paired with factory flat-top pistons and a steel shim .015" compressed headgasket (roughly 10.5:1). I passed MANY 350 powered trucks and suburbans often while towing, all while getting better gas mileage with that combo.

 

Having the spark plug close to the exhaust valve is supposed to be advantageous. Whether that is better than flow bench flow - don't know.

 

I read that you are doing a carb swap and want to put 305 heads on your car

you will have spark knock unless you seriously retard the timing because of the lack of a knock sensor and computer to retard the timing for you

 

You mean retard it because the compression will be higher and I wont have a computer to compensate correct?

Well the heads arent on yet, but I do take that into serious consideration.
Thanks for the heads up!

Also, what do you consider seriously retarded? like 8 degrees atdc? or just at 0 degrees tdc?

 

I ran the 601s on a dished piston 350 with a carb. Timing was normal, just don't crank it up to 36* and expect it to run right. MANY engines run best with as little as 28* of total timing. You don't need 36* in MOST engines.

 

so if i use one of those advanced timing lights, do i hold the engine at 3000 rpms and set it to like 28 degrees? or are you talking about adjusting the vaccumm advance on the distributor

 

You build the engine with the proper parts to control the compression ratio. Retarding the timing to compensate for too high of a static CR is a retarded thing to do. 58cc heads on dished piston 350's typically will run pump gas with "normal" timing.

Where you run the total mechanical timing is based on where the engine runs best at WOT. For most SBC's, that's in the 32-36 range. Vortec heads seem to require less. Vacuum advance, if adjustable, should be adjusted to eliminate part-throttle pinging.