Quote:
Originally Posted by 68 TT
Even if all the parts you use have CARB exemption numbers the whole package still has to pass the tail pipe test so you could still end up with a non-legal combination.
|
Yep, in the end if the emission levels (HC, CO, NoX) are in excess of set limits it makes no difference if parts have CARB number or not.
Quote:
Originally Posted by 68 TT
Don't waste your time on a set of camel back heads. The money you will spend to get a set with accessory bolt holes and to rebuild them and to have them fit with hardened exhaust seats to handle unleaded fuel just isn't worth the end results.
A set of Vortec heads will cost less and stomp the camel humps into the ground if you can get it through emissions. I doubt the older camel back heads will pass an under hood inspection if the Vortec heads won't. I'm pretty sure you can talk the emissions inspector into allowing newer cylinder heads to pass but the older heads not likely.
If you need CARB approval to pass an under hood inspection then the World SR Torquer heads are a great low cost option.
The bigger valve Sportsman heads will lose a lot of low end power especially with such a small cam needed to pass emissions.
|
If you have to pass smog in California, unfortunately, you can not install Vortec heads on your '86 truck.
There are couple of reasons for this due to stupid CA regs.
1) Vortec heads do not have exhaust crossover path used with conventional style EGR valve. Vortec engines (96+ SBC) use an external pipe taped into driver side exhaust to plumb exhaust gases to EGR valve. Vortec engine was introduced in 96 used a linear displacement feedback EGR valve - e.i valve provides position feedback back to PCM.
2) Vortec heads use a unique intake manifold bolt pattern as well. There are no CARB certified intakes since heads were always used with FI.
3) California Smog Nazi's do not like when you mix old with new regardless if your truck passes prescribed limits. The fact that you have (dared) changed emission control system is more important to them. This is a typical eco-Nazi BS - control freakishness aspect that is seem to be in fashion (environmentalist want to see as all on peddling bicycles in near future, like in that Kaiser commercial).
Getting back to your ride (that's what important) - get a EO D# certified or SR (68 TT has a good recommendation) heads and slap EO D# carburetor intake that takes conventional style EGR valve. This way you have all components that have been certified for pre 86 carburetor application.
The 268H cam is better suited for a lighter car application and with 110 LSA it will have a lousy idle quality (low vacuum) - high RPM HP peak. Look for a cam with just a little bit less duration (for example 252-256) and slightly wider LSA (112) for better idle. You will loose just a bit of top RPM, but will have better overall torque. Depending on your tire height I estimate that your 65MPH cruise RPMs to be in 2000 to 2200 range with 700R4. For best (DD) performance your engine should have flat torque in 1500 to 4000 RPM range.
//RF