Mike C Posted August 5, 2001 Share Posted August 5, 2001 Hey Pete, unless they are just given' 'em away, you'll make more power with any of 1/2 a dozen aftermarket heads for less than $1000. The L98 head is only good to about 350hp, even ported with larger valves installed. True the combustion chamber is better and they are lighter, but compression should just about make up for the loss due to lower combustion chamber temps with the aluminum. And if it's not an 85 or 86 L98, you'll have to pony up for a new intake as well with the 87-94 bolt pattern. As far as the d-port exhaust, as long as your header tube is larger than the port, you should be fine. I'm not sure about the angled plugs. If you really want BIG power, switch from the mechanical flat tappet cam to a mechanical roller with 235-240 duration at .050 My camaro has a set of ported 492 and pushes 3500 lbs to mid 12's. The roller cam is the big difference. Check out David Vizards "How to build and modify SBC cylnder heads" from Motorbooks. The ol' iron chevy heads flow pretty good if worked over correctly. He has some 186 that flow 260+ cfm at .500 Quote Link to comment Share on other sites More sharing options...
pparaska Posted August 6, 2001 Author Share Posted August 6, 2001 I passed on them. I talked to a few people about header/plug clearance and it sounded like no fun, even with short plugs. Plus the boss wasn't too happy about any more money going to the Z now - go figure! I'd dumped plenty in the past 4-5 months, and she's right - not right now! Pete "I want better/lighter heads" Paraska Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 6, 2001 Share Posted August 6, 2001 Np pete, kinda grew attached to 'em anyway. Coated 3/4 length headers are made for late model Chev/GMC trucks, available either with or without AIR tubes. Does anyone know if they will work ok on these heads? They're made by pacesetter I think. Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted August 6, 2001 Share Posted August 6, 2001 The only difference in the heads on the pre 87 and 87+ heads is the two center intake manifold bolt holes, it is drilled at a different angle than pre 87 and they have cnter bolt valve covers. The manifold issue is easy to correct. You just bore out the intake manifold bolt holes to allow for a bolt to be inserted at the new hole. Most guys just make the current holes more oblong. It works as far as I have seen.(This is not including vortec or LT4 or etc type heads as they have many other differences) Mike Quote Link to comment Share on other sites More sharing options...
pparaska Posted August 6, 2001 Author Share Posted August 6, 2001 I have a line on a set of L98 heads that have been ported, etc. These would be near ideal for me as I'm using 461 cast iron heads now - more compression, less weight, better flow, better combustion chamber. The only possible downside is that I'm using 1-5/8" Hooker Block Hugger headers. And they've been coated already. That and the L98 heads have angle plug orientation and D port exhaust ports. So I'm wondering if anyone has experience with these or other angle plug heads with the same plug location and orientation (not all angle plugs are in the same place/angle) and they've tried them with the Hooker Block hugger headers. Also, will the flow into the block hugger headers from the D port be o.k.? Not looking for optimal there, just don't want to do something stupid. TIA! Quote Link to comment Share on other sites More sharing options...
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