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I am building a 37 Oldsmobile that I bought as a project car. It already had a 307 Olds out of an '83 cutlass, but I wondering if this engine is worthwhile to rebuild. I want a good cruising engine with some power (275 - 300 hp). Should I just start with a 350 or 455 Olds? Is the 307 worth the time and money for the output I can achieve? Where can I find performance parts for this engine?

[ January 14, 2002: Message edited by: olds37dude ]</p>
 

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having owned a few olds 307's i say go with a bigger engine. other olds engine will bolt right in, and very often 403's are cast out of late 70's trans ams im place of pontiac or chevy engines, might be able to get one of those.
 

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307-350-403-are all small blocks, 400-425-455- are big blocks. The mounts are the same for all of them.350s will be the easiest to find and can be built to run strong. A 403 would be my choice because it's the largest small block. I have had them all at one time or another.The big olds has large rod journals which makes the bottom end heavy and more prone to spin bearings if you rev them to hard.
 

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The 307 olds is a thinwall casting as are 350s after 78 the main webbing will scare you because there is none except some anemic looking cast iron bracing,I would go for a pre 78 block if I were to invest in building an Olds when they had some meat in there
 

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olds W31 was a hi perf 350 with excellent heads and a nice cam and I'm pretty sure the cam is still available and the heads are still around if you look for them, there are plenty of aftermarket parts available also. W30 was a 400 hi perf engine with good heads and cam. most parts are interchangable except intakes and cranks
 

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GRRR 307's are not "Thinwall" they in fact have very "Thickwalls" and have alot of room to play with, why do you think the 307 is the same block as the 350 and 403? GRRR!!! and the mains are not that bad. (heat is seen rising off of head) :mad:

I have a 307 5A head sitting right next to me and there is about an inch between the cylinders! Some of the chevy motors scare me cause they have about .25 inches of room. the collant passages are also not that big and if you are ever that worried you can always sonic test the cylinder walls for thickness. BLAHHH!! mad mad mad.....

[ December 02, 2002: Message edited by: 87442lover ]</p>
 

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Dunno much about them, and not to open a can of worms, it said in Hot Rod Magazine concerning the 403 olds, they were prone to break in the lifter valley in the late 70`s and on blocks due to less meat in the casting when exposed to high lift cams and stiff valve springs, they did not recommend these blocks for high performance usage.
 
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