Upgraded Valves

THE BIRDMAN

Registered User
Hey everyone I got a set of 94 heads that I plan on getting ported and polished and I was wondering I know our stock valve size is 1.78 intake and 1.45 exhaust with 7mm stems. Now what I'm wondering is I've read where you can upgrade the valves to a larger size while still using the stock seats so if this is the case what size valves can you run while keeping the stock seats. Can you run 1.85 intake and 1.55 exhaust with the stock seats? If not what is the max size you can use with the stock seats? Also what length are the stock valves are they the same length as SBF valves and what stem size is everyone using? I know with 7mm stems the valve selection is limited. So that leaves me with either 5/16ths or 11/32nds stems can either of these be used with the stock valve guides I know they'd need to be honed etc.Or would the guides need to be changed to upgrade the valves.I would think it'd be a worth while and semi cost effective to upgrade the valve sizes while still using the stock seats since the stock valves are so tiny.As I think it might be cost prohibitive to go to valves so large that would reuire you to have new seats installed which I would think would be a rather costly option.If I do upgrade the valves to a 5/16th or 11/32nds stem valve wouldn't that also open up to a ton of cheap valve spring/keeper/retainer options since I'd no longer be using the semi oddball 7mm stems.Just some thoughts so tell me what you all think.Or should I just have the heads ported and use stock valves?


Thanks
Jay
 
Our valves are not 7mm so forget all that junk. 1.840/1.570 are the biggest that will go on stock seats and they are not SBF, they are Chevy. Shop around but I've got them on the shelf ready to go. You know how to get a hold of me if you are interested. ;)
 
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