Harveydent13

I'm having trouble finding aluminum heads for my 78 delta 88, the descriptions only say 1976 and older. Will they work the same? And also I can't seem to find a dual exgaust setup for this car, will I have to piece one together? Thanks

joe_padavano

Olds changed from 7/16" to 1/2" head bolts after the 1976 model year. You will need to open the bolt holes in any aftermarket aluminum heads to fit the 1/2" head bolts on your motor. I assume it's an Olds 350.



Olds never offered a dual exhaust system on the 1977-1990 B-body cars. The good news is that the chassis is the same as the one used on the 1991-96 Caprice/Impala. Walker Dynomax sells an aftermarket 2.5" cat-back stainless dual exhaust system for the Caprice that also fits the 1977-90 cars. RockAuto carries it. You will either need to modify your trans crossmember or find one for the 1994-96 Caprice that already has double humps for dual exhaust.

Olds64

Don't forget to take your car to a local exhaust shop. They might be able to beat the price of the Walker setup Joe mentioned. Plus, a good shop owner can help you decide on what mufflers to install.

joe_padavano

The Walker system is mandrel bent. Nearly every muffler shop will use a conventional bender that crimps the tubes at the bends.

oldcutlass

Will that even matter for a stock 78 350 in a Delta 88 with 170 earth shaking HP?

Olds64

NVM, I see it's stainless.

joe_padavano

He's asking about aluminum heads. That tells me it isn't a stock 1978 350.

Harveydent13

It won't be stock. Heads, headers and intake will be going on, but the exhaust on it now is shot so i might as well go duals now

oldcutlass

Are you doing anything to the bottom end, like better pistons?

Harveydent13

Is that recommended? I'm only looking to have a little more power, it's going to be a street car.

Olds64

If you are looking for a street cruiser then save the money you would spend on aftermarket heads for other upgrades. Dual exhaust with headers and an intake will do plenty for your butt dyno.

oldcutlass

You know what happens when you assume.

Half the story...

I had to ask...

Harveydent13, I'm not making fun of you. Spending that much money on alum heads, carb, intake, and possibly a cam. Not doing anything to the lower end to boost compression is a fruitless exercise. Compounded by adding an extremely expensive exhaust, you accomplish nothing, in fact it may make it run worse.

Harveydent13

No offense taken, I'm extremely new to Oldsmobiles, and older cars with carbs (I'm only 25 so a 78' is old for me haha) any input is helpful

oldcutlass

Its great getting more younger people into the hobby. Reading and asking questions is the logical way to research to make sure your money is well spent and your goals are achieved. This approach is applicable to any brand car.

Harveydent13

I've been into Volkswagen and bmw, never really stuck and my step father bought me this car and I love it. I'm trying to research everything as much as possible before going forward with anything. I considered a mild 403 build on the side

oldcutlass

Yes, I remember your first post, that your car only has 28k miles on it. There were quite a few valid suggestions made. Read the engines section for builds in your price range and since your contemplating a 403 you can also consider a 455 swap.

joe_padavano

When the OP says that he's looking for aluminum heads, I'm not assuming.



The original 3A heads have 75-ish CC chambers. It doesn't take much milling on the aluminum heads to bump CR without changing the pistons. I personally wouldn't do it that way, but it doesn't suck.




Extremely expensive is a subjective term. The Dynomax kit I showed is $761 from Amazon. RockAuto currently shows it out of stock. I have no idea what a custom bent dual exhaust system with mufflers goes for from a muffler shop. Most shops here in Northern VA don't even do custom work like this any more.