loveda88

I have a 1985 Delta 88. It has the stock 7A 307/200-4R. I have a solid lead on a 1969 350 Rocket. Has anyone done this swap? Biggest thing I'm worried about is how to make the exhaust work. Any ideas? Anything else I need to worry about? Any advice or tips yinz might have would be super helpful! Thanks!

olds 307 and 403

Are you wanting the pathetic stock exhaust? If so, get a set of 73 and up manifolds or the 80 to 84 307 manifolds with the O2 sensor, if you want the CCC. Don't use the tubular manifolds. Or just use the early 350 manifolds and a custom dual exhaust system. I believe the 70's A body dual hump crossmember will work. Are you wanting to run the CCC system? It can be done as well, especially the 2bbl motor as is.

loveda88

The CCC system is long gone. The exhaust is stock up to the cat. Ideally I could hook it up to that, but if not, I'd like to know what to do. I do have a set of 5A exhaust manifolds. I also have a Edelbrock intake to swap on so I can put a 4 barrel on. A dual notch crossmember would be excellent, are you sure that would work? Anything else to worry about?

joe_padavano

It's a bolt-in. The two motors are externally identical. As with any Olds swap, use the water pump, pulleys, and accessory brackets as a matched set to avoid belt alignment issues. The 307 brackets bolt to the 350.

loveda88

Awesome thank you! Any advice on what to do about the exhaust?

joe_padavano

Depends on your cashflow. It's kind of a waste to put in a more powerful motor and then give it constipation with the stock exhaust, but that's something you can easily change later.

loveda88

I agree, but given the single notch crossmember, I'm not sure what to do. As it is now, it's a custom dual set up after the cat. Can I hook it up to the stock pre-cat exhaust with minimal bullshit to at least get it to the shop? Cash isn't exactly restrictive, but I also don't want to just burn money

joe_padavano

Yes, you can use the existing pipes to connect to the current system. As noted, I'd use the 1981-84 cast iron manifolds and not the 1985-up tubular ones. The crossover pipe and down pipe from the 307 will bolt up. A Caprice double hump crossmember for your trans (200-4R and TH200/TH350 use different crossmembers) will bolt in.

loveda88

Okay just making sure I've got this right. I bolt the 307 5A exhaust manifolds on to the 350 and use them to connect to the rest of the exhaust system. Just for the meantime. And I have a 200-4R in there now, so what year Caprice crossmember should I be looking for?

joe_padavano

The only factory double hump crossmembers were on the Impala SS with 700R4, so for a 200-4R you'll need an aftermarket one or modify yours. The 1977-1996 Caprice crossmembers interchange.

loveda88

Any suggestion on where to look for an aftermarket crossmember, and what to look for exactly. Searching things for an '85 Delta doesn't yield much in the way of results sadly. Not too many people refreshing those cars

joe_padavano

Which is why I suggested searching for a Caprice of the same year.

https://www.summitracing.com/parts/s.../model/caprice

loveda88

Oh, excellent, thank you!!!