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Old 12-21-2011, 04:54 PM
DrVette DrVette is offline
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ok i think i would probably go with a carb intake and an adapter,because of the cost. and also what about the computer,and all the extra sensors such as the o2 sensor because my truck already has " true dual" exhaust?
NO NO NO NO, the fuel consumption of an non-ECM controlled engine will far outweigh even the cost of a $400 intake.
Get the calculator out and test what I said.. my base for conversions w/mpg concerns is for 100,000 miles, easy math that way.

I expect fuel economy on your "87 Suburban to drop from say 12-14~mpg to 8-10mpg~ AND a serious loss of power.

For a Suburban, You want torque AND economy.
Scrap the duals for a large single system.
A large single tube will meet any pulling needs you have.
Too much exhaust flow lowers back pressure, raising the torque curve and killing mpg.
MORE, back-pressure lowers your peak torque curve and increases fuel economy.

The Vortec to TBI intake looks most promising to me. Vortec TBI Intake at Jegs

A Vortec Long Block topped with a TBI / TBI Distributor and all the original TBI stuff hooked up and you're good.

[[U]The exterior stuff, like the Harmonic Balancer, and its Size, Belt width and depth, and accessory mounting holes, etc I do Not know!!.

Timing marks are NON-Existent on a Vortec, someone Shout about how to get some idea on this issue..

Make sure to replace the knock sensor off your TBI block, it's near the freeze plugs, as well as the O2 sensor EGR, MAP and all others

GM made it pretty easy for this, the last time I did some work on a TBI, I noticed the plugs were different and would not interchange, dunno if this is still the case.

You MAY need to get a flash done on your chip if you encounter spark knock or other oddities.

A benefit to the TBI engine is that you can actually set your timing.
On the OBD-II Vortec engines, the computer will re-set the timing if you jack it up too high.
Timing set too Low on the Vortec gives a rich code setting. Odd huh ?

"True' dual exhausts do not mean you have no fitting for a O2 sensor.
Usually they cut the pipe just before the converter, the o2 sensor is high up, near the flange.

One user said, "on some model years, the Vortec exhaust manifolds are different than TBI",
I don't have a clue on this.

Just make sure to use the TBI O2 sensor however it works out.
The "Y' pipe on the donor vehicle and exhaust manifolds may be necessary, grab the catalytic converter too, while you're at it.

Set up your TV Cable to the trans, do it right the 1st time, reading up on TV cable setup procedure may prolong your trans life as the TV cable controls pressure.


Last edited by DrVette; 12-21-2011 at 05:00 PM.
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