john-dickjr

iTrader: (2)

will the L92 heads fit on the 5.3 liter motors? i heard that they will but you can not use them cause of the big valves of the l92, while others say yes it will work ..

04600rr

iTrader: (12)

i just read a car craft article that said it will not work

battsup

The reason you can't use them is because a 4" bore is required for the head.

sierrac3_s2000

iTrader: (6)

Check Mast Motorsports. They have L92 style heads for the smaller bore. But you are correct that the GM L92 heads have to have a minimum of 4" bore.

Jimbo1367

IIRC.. GMPP has a L92style head now for smaller bores. I think its because they use a smaller intake valve. I would think the intake port would be too big for such a small engine. Might be better to get ported OEM heads or AFR or TFS 205CC heads.

avmechanic

Looks like GMPP has a L92 style head available now for small bore engines but from the info I see you would still have to bore the 5.3 to std. 5.7 pistons at least to work. Sounds like a doable project though. Here is the info.

PN. 19201807 LSX-L92 Small Bore Cylinder Head Features:

*
L92 style rectangle port design
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Assembled with 2.000" intake and 1.550" exhaust valves
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15 valve angle
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Requires a minimum 3.890" bore for valve clearance
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250cc "as-cast" intake ports, 80cc "as-cast" exhaust ports
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65cc "as-cast" combustion chambers
*
Uses LS3 rocker arms/LS7 bolts

Greg