350 Olds Engine

Jim H.

Jim H.

Greasemonkey
Nov 13, 2011
123
18
Dayton, Ohio
Picked up an Olds engine today the original owner died picked it up for a couple cases of beer hopefully this was a good deal let me know your thoughts. Figured if anything went wrong with the 307 in the H/O this block will fit nicely.
 

Attachments

olds307 and 403

olds307 and 403

Comic Book Super Hero
Oct 14, 2008
4,519
113
Melville,Saskatchewan
77 to 80 Olds 350. Windowed mains, crappy flowing, crack prone heads and the same output as your 307 HO stock, give or take. Early 350 heads, the new Mahle 1mm ring pack pistons and a decent cam would go a long way.
 
Hypn0tic

Hypn0tic

Not-quite-so-new-guy
Jul 10, 2018
39
18
Would be a nice street cruiser engine with a mean sound. Any serious power will seriously interfere with reliability.
 
Jim H.

Jim H.

Greasemonkey
Nov 13, 2011
123
18
Dayton, Ohio
My plan was to scrap everything but the block and have it bored possibly then figure out what heads will work best. Everything on my 307 like the exhaust, starter, performer intake I think will work on this motor. Or would I be better off to find an older let’s say 1972 Oldsmobile 350. Also I believe most of my brackets will work with this motor also.
 
Hypn0tic

Hypn0tic

Not-quite-so-new-guy
Jul 10, 2018
39
18
Anything from 68 to 76 will be a good platform to build hp and tq. The problem after that arises in the bottom end of the block. There simply isnt enough meat there to stop the crank from flexing too much, or the block actually cracking. There are methods to beef up the bottom end of your block ( Dick miller racing has everything covered). That being said, its extremely pricey as opposed to building a 68-76 block. If you do build your engine, Keep it mild or you may be in for a bad day.
 
olds307 and 403

olds307 and 403

Comic Book Super Hero
Oct 14, 2008
4,519
113
Melville,Saskatchewan
The pre 77 blocks are better to build. The stock gray iron crank is supposedly good till 400 hp. It is weaker but lighter than the nodular and forged cranks. Those Mahle pistons I mentioned are lighter than stock which helps. Any 4 through 7a 330/350 heads will bolt right on after drilling out the head bolts, one dowel hole and flow better. 1through 3 will also work but need the pushrod holes opened up. 1 and 2 have unique valve train's making parts harder to find. Add W31 valves to whatever heads you find.
 
fleming442

fleming442

Geezer
Dec 26, 2013
6,429
113
For your average street machine, the window blocks are fine; a well built 403 will put you in the low 12s pretty easily, and it has windowed mains. By "well built", I mean a proper selection of off the shelf parts- nothing exotic. Of course, proper machining is a requisite. What part of the continent are you in? There are good Olds guys all over the US and a few in Canuckistan I'm aware of.
 

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