Inliners International Forums General Discussion Hi Performance Lumped 250 Head on a 292 and a few other questions

I bought the lump kit from Tom Lowe, and then decided I didn't want to alter the stock head. So I bought one with the lumps installed from Mr. HotRod 6 on Ebay. When I got it I checked the casting number and it is from a 1975-85 250.

I am still fairly new these engines, and I didn't have the opportunity to check the 250 head against the 292 head before taking it to the machine shop. I assume they share the same bolt pattern for mounting it the block, intake and exhaust? Will the 250 head be a direct swap onto the 292? I hope so. The 250 head is getting 1.94/1.60 valves installed. It has 72.7 cc combustion chambers.

I also noticed the spark plug holes are not as big as the old 1966 292 head, so I am guessing GM went with spark plugs that were used on the V8's?

I know I should have done this before taking it to the machine shop, but I want to gasket-match the intake and exhaust ports, how difficult is it to remove the valves to do this after it is an assembled head?

The set screws for the lumps, do those get ground down to blend with the lumps, or do they stay long and stick into the intake ports?

I am not going for race power, just want the 292 air pump to breathe more efficiently is all.

Does Tom Lowe's ductile iron dual exhaust manifolds work with the clutch linkage on the trucks? His website says the z-bar needs to be modified on the manual transmission cars, just no mention of the truck z-bar. I plan to run the stock exhaust at first, but will eventually get the dual exhaust and want to know what modifications need to be done prior to purchasing.

Thanks,

Shane

All heads from 194,230,250 292 will interchange. Just the 194 has the smallest CC chamber. Their are a few 194 heads that had close to the same CCs as the others, but most where small CCs. YES the lump bolt can be cut off with a dremel size disk. Yes the heads did have to different size plugs 5/8s and 11/16?? . One has a tappered seat the other used a washer to seat.
If they put PC seals in the head you will have to replace them if you remove the valves.
Sorry I can't help you on the exhaust. mainly because i don't use them I build my own headers.

Thanks @Twisted6, that helps a bunch. He is going to put the PC seals in the head. Are those difficult to install?

No and there is a install tool for them and that's pretty cheap.