after about two months of searching I found some W-30 (high performance manifolds) RH-402294 "Z" and LH-412287 "Y" (sub for 402295). I assuming these are for the big blocks but will fit the small bock 350.

I went to have the manifolds surfaced and broke studs tapped and new studs. The cost is $60.00 for resurfacing and $30.00 for the studs.

the LH-412287 has a surface crack.

Now, OPG has the small block version of the W-30 manifolds for $307.00.

With the cost for the manifold, $90.00 for surfacing and possiable cost to make the exhaust bolt up. Are the old ones worth the cost or will the new ones live up to the hype?

thanks,

ron P

 

Hey Ron, welcome to the site! Sorry, the big block manifolds won't fit on a small block. Read through this thread about the repop small block manifolds:

https://classicoldsmobile.com/forums...manifolds.html


John

 

Welcome to CO Ron.

 

Welcome aboard Ron

 

Welcome.

 

Welcome, Ron
Don't get too excited about your "W30" manifolds. That is totally misleading terminology. They's the same as any other 442 manifolds.

 

Just to add a little, the 412287 should be an "X" casting code, not a "Y". The good news is that these are both internally divided runner manifolds. The bad news is that they will not fit a 350. They will bolt to the heads, but they won't clear the motor mounts. The big block manifolds are sized to take advantage of the taller deck height on the 455.

As for the repro "high performance" manifolds for the small block, you might find this thread interesting:

https://classicoldsmobile.com/forums...manifolds.html

 

Welcome to our site!!

 

thanks all, I will order the small block ones from OGP for $311.00. Any one interested in the big block (W-30) manifolds I have? I paid $150.00 for the pair.

Thanks,

ron p