Who can help with an Olds 350 head?

[Woodfin]

A fellow has contacted me in question about rebuilding a 1971 Olds Cutlass 350 original engine. He wants to increase the performance within reason. I know the customer and his car and his style so a factory iron head will be the best choice. It there a factory head better that the 1971 350 model? And is such a head easily available. I would like to make him a 400 horse package.
Who is in the know with Olds 350 heads? And for that matter, 350 Olds engines in general.

[Paul Precht]

A good start would be putting in the 2.005" intake to replace the 1.88" and some pocket porting.

[Dave Siltman]

I’d suggest 1968-1969 #5 or 1970 #6 heads. You’re gonna need more than just a head swap to make 400 hp, though. I’d recommend a bit more compression, a respectable cam and valvetrain upgrade, a Performer RPM intake, a decent pair of headers, and a reworked Q-Jet. 400hp is achievable and if maintained and not over revved, should be stout and live quite a long time. You should be fine with a factory crank and rods (reconditioned) at that level.

[SSDiv6]

Originally Posted by Woodfin

A fellow has contacted me in question about rebuilding a 1971 Olds Cutlass 350 original engine. He wants to increase the performance within reason. I know the customer and his car and his style so a factory iron head will be the best choice. It there a factory head better that the 1971 350 model? And is such a head easily available. I would like to make him a 400 horse package.
Who is in the know with Olds 350 heads? And for that matter, 350 Olds engines in general.

Keep the 147 castings and put the larger 2.07" intake and 1.625" exhaust valves with some porting. Install rocker arm studs and guide plates and put some Harland Sharp roller rockers which have the proper geometry for Olds engines. Other brands use a Ford rocker that does not have the proper geometry.

The best intake is either the Performer RPM or Holley Street Dominator if you can find one.

I would also recommend the use of a hydraulic roller with Johnson Lifters, for Pontiac/Oldsmobile applications. The Chevy lifters have the oil band in the wrong location.

[Greg Barsamian]

Originally Posted by Woodfin

A fellow has contacted me in question about rebuilding a 1971 Olds Cutlass 350 original engine. He wants to increase the performance within reason. I know the customer and his car and his style so a factory iron head will be the best choice. It there a factory head better that the 1971 350 model? And is such a head easily available. I would like to make him a 400 horse package.
Who is in the know with Olds 350 heads? And for that matter, 350 Olds engines in general.

Contact Sam Murray, Mr. Oldsmobile.......

[Rich Biebel]

I just watched a video of some dyno testing on a 70 W-31 350 Olds engine
10+ to 1 compression with 2.07 intake valves and the factory aluminum intake with headers
It made exactly what the factory rating was 325 hp at 5400
Was a stock cam and freshly rebuilt +.030 engine

Could one make 400hp ? Sure but it obviously would take more than just some different factory iron heads !!

[Jim Kaekel]

First question you need to know, is this car going to be operating on non-leaded pump fuel? If so, you'll need to use a cylinder head with hardened valve seats. If you want 400+ horsepower out of a 350, I would recommend a set of Edelbrock heads along with an Edelbrock or Holley Dominator intake that can be ported to match the heads. By the time you prep a set of OEM heads, you would be further ahead with the Edelbrocks. Add a set of forged pistons, camshaft that would make power to 6500-7000 and upgraded valve train with beehive springs. Don't forget a good set of 1-3/4" or so headers and free-flowing exhaust. I would use a race-prepped Q-Jet but that's just me. If it's a street car, a minimum of 3.91 rear gear out back will be required.

[Danny Byrd]

Olds made a 17 degree alum head for their Diesel block back in the 80's. That head would make a lot of power but they are hard to find. Someone on here that knows Olds better than I could tell you if the stock block & the Diesel have the same bolt pattern.

[SSDiv6]

Originally Posted by Danny Byrd

Olds made a 17 degree alum head for their Diesel block back in the 80's. That head would make a lot of power but they are hard to find. Someone on here that knows Olds better than I could tell you if the stock block & the Diesel have the same bolt pattern.

You are referring to the Batten cylinder heads.
The diesel block, although stronger, has a larger main size as the big block Olds. Some racers use spacers in the mains with the small block bearings. There was also a limited run of Olds small block racing blocks that are hard to find. For a low cost small block forged crankshaft, you can use the Olds 330 crankshaft, however, you have to use the corresponding Olds 330 or 425 flexplate.