falconsfan

I am in the planning stages of this and hope to find someone who has successfully accomplished this to help guide me through the process.

I'm looking to get 275-300 HP from the '73 Olds 350...Nothing radical..Dependable, low maintenance, but power when I want it....Not sure how to get there. Ive heard that I should use the 307 heads and intake on the 350 block? I can get away with the lack of emissions stuff.

Not sure if I should keep the computer or not but I do want the original gauges to work.

Not sure if I should change the trans to T-350 or keep the OD Trans.....I have a '73 crossmember (it has two humps for exhaust).

Any help would be nice.

Redog

Emissions depends on your state, usually anything 75 and later needs emissions. Here however classics and antquies do not require emissions testing. I put Classic plates on my car becuase I plan on dropping a early 70's Olds motor in my car too.

The Compression of a 73 350 and up is 8.5 to 1. The 307 you have now is the same compression ratio or it's 8.2 to 1. The first thing you want to do is get that motor rebulit and put in high compression pistions. Mondello and Dick Miller racing both have them. Then is depends on the heads you use. Don't go out and spend the $1500 or more on the big block heads becuase this will drop the CR back to stock or close to it.

www.mondellotwister.com has a set of pistions for the 350, when used with a 64cc head (like 5, 6, or 7 heads, 5 is the best) will give you a nice beefy 10.26 to 1 CR. They are $360 for the set and come with everything you're going to need to bolt them to the stock rods.

You can't use the exhaust manifolds, intake manifold, or heads from your 307. Any 307 intake made after 1984 has smaller ports and will choke the 350 for air. The heads are also too small of a port. I'm willing to bet you have the 7a heads on there. I've read that they don't work well on a swap to a 350. 307Exhaust manifolds where always too small for a 350. but you have a Cutlass. Throw on a cheap set of headers and a nice Flowmaster Super 40's with "X" pipe duals. You can get the entire set up fom Summit or Jegs. "X" pipes equalize pressure from both the left and right banks which is better for combusion.

Also get a Elelrock Manifold like a toqurer or something. The basic Elebrock manifold is the same thing as a stock Olds Manifold from back in the day, so to save money, you can get that now, and do the bigger manifold later.

Do forget to get a decent carb. You can get the q-jet rejetted. This is a guy running 11's with a 60's something Cutlass using a modded out q-jet.

New cam will help too. Also on Mondellotwister.com. You can get either a JM 18-20 cam or a JM 22-25 cam. Just be sure to get all the springs, rockers, and lifters too. While you're in the heads, I'd do new valves too. Stock size, but stainless steel, very nice.

K&N filters will help get you to your goal too. You can also pick up an air intake kit from http://www.ramairbox.com/ This will give you a dual snokel intake set up.

Tranny and rear end gears help too. Not in horsepower, but on moving that car off the line.

This could get you in the area of HP you're looking for, maybe more

Redog

I would keep the OD trans, but don't get rid of the 350 trans yet

Redog

I've done a little bit more reseach on this question about the heads. The 7a heads with the 0142 casting will not fit any of the aftermarket intakes out there. If you have the 5a heads which were 1980 to 1985 and have the casting 3317 will work will all aftermarket intakes

Jim's rare 80

Hey. I've got what you're looking for. I replaced the 260 in my 80 Cutlass, with a freshly rebuilt 350, which I originally built for my 73. (73 got a 455 instead.) Here's the basics, specs are in a filing cabinet. 73 block, bored 0.30 over, stock bottem end. 71 heads,(bigger exhaust valves), 80 delta 88 350 intake, not ported... yet.. (for egr valve), mild cam. No change in rise, just valve duration, no mods to heads for that, rochester 4bbl from same intake, rebuilt, stock primaries, secondaries changed to 69 w25 specs/rods.(I think) It's up against a th400 tranny, rebuilt with a shift kit. The best upgrade was a bual snorkel breather, which I made myself. (see attach) The car will break loose going into second now. Main upgrade!!! Air intake, and car passed it's last required e-test, without the air pump. (Ontario, mind you.) PM me if you want more specs. Good luck. Jim.

falconsfan

Thanks for the info folks....Very useful.

79cutlass

i have heard of people takeing a 307 and taking the craink out of it and swaping the 307s crank out with there 350s. I heard it is supose to make you rap out quicker. I think that would help you with some power.

joe_padavano

While I'm not sure what "rap out quicker" means, ALL Olds small blocks (260 through 403) use exactly the same stroke. Swapping a 350 crank into a 307 changes exactly nothing. Now, the 64-67 330 cranks are at least forged, but still have the same stroke. Also, note that this thread is a year and a half old.

Sanghi

Hey what can you tell me about the 350 from the delta 88 I'm in the middle of a swap and need help anything would be appreciated

olds 307 and 403

I can tell you this thread is 7 years old, falconsfan probably doesn't own an Olds anymore. You have to tell us what year Delta, as the 350 was an option between 68 and 80.