whats the best year for olds 350 motor?

[Pearl86]

When I start looking for my 350 to swap out my v6 just wondered which year or years has the strongest 350 or if there is a good year for the 307 motor.

 

[Dragonist]

look at the casting #'s on the blocks next to the oil filler neck...your looking for casting numbers for blocks that are solid mained

1 '64-'66 330 381917 45° cam bank angle.
1A 330 381917 45° cam bank angle.
2 '68-'76 350 381917
2 '68-'70 350 395558
3 '66-'67 330 394417 39° cam bank angle.
4
5 '73,'74 350 395558
2A '75-'81 260 Solid main webs for 2A's only? At least for '76.
2B ??-'81 260 557751 Windowed main webs. Windowed main webs for 2B's only?
3A '79 350
3B '77-'80 350 557752
4A '77 403 557265 Solid main webs possibly
553990 for these three
554990 casting numbers.
4B '77-'79 403 557265 Windowed main webs always.
?? '85 307 556607
5A '81- 307 3161
D3 350 7582 Diesel

 

[CUTLASSJESSE]

a 68 block is the best 350 kinda rough to find though

 

[DoubleV]

Untill you get into the crappy windowed blocks of 77+, pretty much any olds 350 block will do. They're basically all the same.

If you are looking for a complete engine w matching set of heads, 68-72 are the best because they had the good flowing heads. 68-70 will also have higher compression ( more for the 4 barrel carbs and less if they're from a 2 barrel ). 71-72 had lower compression ( even lower than the 2 barrel 68-70 350's ), but still had the good heads.

In a nutshell, just try to stay away from the 77-80 350's with there matching crappy 3A heads.

 

[bill]

Ditto.... I just wanna add that the 68-70 blocks had a higher nickle content, which gives the cylinder more strength and keeps the rings from wearing out the walls. My engine had 70k miles or more when I tore it apart...no kerf around the top of the cylinder and no wear along the walls... amazing.

 

[1985cutlasssupreme]

1970 cutlass 350 gold blocks made good power.

 

[CUTLASSJESSE]

it all depends on what you want ti do with it a DX block is the best olds 350 block out there in stock form....but that being said its a deisel block so would be a large investment gas block anything before 77 is good till about 400 hp

 

[87ttop]

I got a family member with a complete running driving 69 cutlass 4 dr with the 350 gold rocket and it runs like a champ if anyone is interested

 

[outsider_27]

The 77-up blocks are fine if you are not going to outright race them. They are good for mild performance. Mine is a 77 and I tore it apart at 115K with absolutely no cylinder wall wear. Just did the cross-hatch to seal the rings and that was it! And if yo are going to race it they make girdles to strengthen the bottom end more. The heads are the worst part, and there are better heads available. Find an early set of heads and you'll be good.

 

[Rocket]

it all depends on what you want ti do with it a DX block is the best olds 350 block out there in stock form....but that being said its a deisel block so would be a large investment gas block anything before 77 is good till about 400 hp

the windowed 350 blocks can easily handle 400+HP