EL CAMINO Swapping heads 305 HO question

[Rowshak]

Hi,

I'm about to swap the heads of my 1981 305 for 80-86 HO 305 heads.
The main reason is that I can't stop the valve cover to stop dripping oil. The previous owner sanded the top of the head to clean it, and every year I need to change the gaskets once they start sitting well.

So I have found cheap 305 H.O heads with the springs and everything. I'm just not sure if it's a good idea. Will this influence the motor in any way?
I'm not investing performance in my 305; I want it to stop dripping.

If I switch motor, I will go for a full crank seal instead of those half moon seals before going for a performance engine.

Thanks,
John

 

[565bbchevy]

Changing heads seems extreme for a valve cover gasket leak, what have you tried so far for gaskets and valve covers?
A set of cast aluminum valve covers and some thick reinforced gaskets will usually seal good.

 

[Rowshak]

Changing heads seems extreme for a valve cover gasket leak, what have you tried so far for gaskets and valve covers?
A set of cast aluminum valve covers and some thick reinforced gaskets will usually seal good.

I know. I tried the thick plastic gasket and the liege gasket both drip. The main problem that I figured is the round shape the head has.
The previous owner sanded the top of the heads with a sandpaper either a 40 or something more coarse.
The roundness + the deep scratch prevent it from sealing properly.
I did think about trying to sand it but I may just worsen the problem. So since I can get those head for 30$ for both, I thought it could be a cheap way to just save time and hassle.

At the same time, I'll change the head gaskets.

 

[565bbchevy]

I tried the thick plastic gasket and the liege gasket both drip.

I don't know what "plastic" gaskets you would have used and I don't know what you meant by "liege".
Do you have stamped steel valve covers?
Are these cast iron heads if so unless the previous owner used a grinder on them there is not much sandpaper is going to do to alter the shape.

 

[Rowshak]

Sorry, I meant gasket made of rubber and the other is cork.
For the covers, I had the original Caballero's valve cover and I switched them for the steel ones that I had in the garage. Both sets are straight.
For the scratches, they are deep like a coarse 40 would have done.
The heads are cast iron.

P.S: Sorry for my English, I try my best to be as precise as I can.

 

[565bbchevy]

I did think about trying to sand it but I may just worsen the problem. So since I can get those head for 30$ for both, I thought it could be a cheap way to just save time and hassle.

I personally would question swapping a used pair of cheap heads without spending the money to have them checked out, they could also need work and might have some comparability issues with your current set up.

For the covers, I had the original Caballero's valve cover and I switched them for the steel ones that I had in the garage. Both sets are straight.

If you can post pictures of what you are working with as far as gaskets, valve covers, the heads where you suspect the sealing issues are at would be great.
But I would get a set of cast aluminum valve covers that will (fit short or tall) depending on your set up and then buy a set of these valve cover gaskets.
https://www.summitracing.com/parts/fel-1604/overview/ and clean the mounting surfaces well and then lay a bead of RTV on the head rail before installing and it should solve any sealing issues you have.

 

[Rowshak]

Thanks for the advice.
Right now, I'm doing some work on another vehicle, but the El Camino is the next-in-line. I will check it out, and post some pictures later on.

 

[Turbolq4]

Or ditch the gaskets entirely and just use black rtv. Clean the surface with brake clean, roll a nice bead on to the head and let it skin over for an hour or so. Slap the valve covers on and snug them down. Wait overnight to tighten them down fully.

Shouldn't be ultra difficult to remove but will have plenty of sealing area.

 

[Clone TIE Pilot]

Pre 86 HO 305 heads should fit fine on a 81 305. The HO heads have bigger valves and a little better flow for more power.

How is your PCV system? Any problems with it can cause crankcase pressue to increase and cause oil leaks. Some brands list the wrong PCV valve sometimes.

I use neoprene coated steel shim valve cover gaskets from Jeg's private label and had no valve cover leaks.

 

[Rowshak]

Or ditch the gaskets entirely and just use black rtv. Clean the surface with brake clean, roll a nice bead on to the head and let it skin over for an hour or so. Slap the valve covers on and snug them down. Wait overnight to tighten them down fully.

Shouldn't be ultra difficult to remove but will have plenty of sealing area.

Thanks for the info.
I wouldn't try it on the OEM covers but I could give it a shot on my other set of valve covers.