Sorry if this is posted but could not find

[RoyBob]

Old school Carb guy here, Not use to the TBI stuff So
My 1989 350 Is stock I have done timing chain /gears/ and intake gaskets I know the engine has the drilled holes for the Roller Lifters spider/Hold down. I would like to install a nice Cam Rough Idle Like the Muthathumper Cam I have done a few and sound great !

So Friends Tell Me what my options are

I would like Headers We have zero Emissions Here ( Alabama )
Not concerned how fast i can go Just like that Nice Cam Lope So a set of roller Rockers/ Lifters/And Cam
I rely don't want to Get away from the stock look under the Hood .
Open to suggestions on this Thanks In Advance !! Any help would be great Old Guy RoyBob Here .....
My questions are

 

[95burban]

That will require ecm tuning if you keep the tbi

another option is to put a nice intake and carb on it with a nice set of heads and a better cam.

Me personally, your truck is a time capsule. I wouldn’t mess with it. It’s a beautiful rig.

 

[movietvet]

What @95burban said. The TBI system is pretty easy to understand and is more efficient than the carb and less finicky. You can still do headers.

 

[RichLo]

Thumper cams are the worst of all worlds, they are literally just for sound.

If you want a lopy idle and are already doing roller lifters and rockers, at least get a high-RPM cam to get something out of that terrible low RPM performance.

Or, If your just going for sound, unplug 1 spark plug wire when you want that performance idle, lol.

 

[RoyBob]

That will require ecm tuning if you keep the tbi

another option is to put a nice intake and carb on it with a nice set of heads and a better cam.

Me personally, your truck is a time capsule. I wouldn’t mess with it. It’s a beautiful rig.

Thank You It even has zero rust or wrecks

 

[RoyBob]

Think i may just do Headers and Exhaust

 

[Vikingdude]

It's pretty tough to get primitive EFI systems to work well with a choppy idle. If you want that sound, carb conversion s probably the path of least resistance.

 

[L31MaxExpress]

Thumper cams are the worst of all worlds, they are literally just for sound.

If you want a lopy idle and are already doing roller lifters and rockers, at least get a high-RPM cam to get something out of that terrible low RPM performance.

Or, If your just going for sound, unplug 1 spark plug wire when you want that performance idle, lol.

I do not necessarily agree having worked with a couple. They have a bit more exhaust duration split than I like to see for low rpm torque, but the tight LSA and longer exhaust duration really flattens out the midrange and top end torque curve. I helped a buddy build a smog era 350 with what he had. Was your typical mexican goodwrench engine. 12cc dished pistons, 993 76 cc heads, etc. The block was punched 0.030 over, substitued flat tops with a 1.56 compression height. Zero decked the block. 0.038" compressed felpros. It was something like 9.4:1 with the 76cc 993s. Put the necessary springs and the smallest flat tappet thumper. RPM air gap intake with a 750 double pumper because he had it. Long tube headers, 2.5" pipes into flowmaster 40s because had them already. Put it into a 1979 C10 short bed step side. TH350 with a 2,500 converter and 3.73 gears. I dialed in the HEI and carb. That truck proceeded to run 8.90s, then 8.80s, then 8.70s in the 1/8 in Texas summer heat all evening long. That was on Cooper Cobra P275/60R15s aired down to 24 psi in the rear (max cold inflation in the front) with an open diff as well. The truck probably would have gone 8.30s on drag radials with some kind of locking or limited slip differential. It never broke a 2.10 60' due to traction. The truck got faster the more the engine broke in even though it had about 500-1000 street miles on it already. It had not been really flailed on until the track runs. Some there refused to believe it was a smog head 350 with a thumper running those times.

That being said I do like the Lunati Bootlegger better and do not like the Howards Rattlers.

 

[L31MaxExpress]

Look at how far the power spread is between peak tq and peak hp on this 383 with a Thumper. With the 10:1 static compression and iron 200cc heads it is no slouch. 480+ hp and tq. Torque peak at 3,100 rpm and hp peak at 6,000. The torque curve just hangs on and it keeps making power. My 383 makes a bit more, but it has better heads, more compression and was cammed with an emphasis on midrange torque not peak HP or RPM.

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[L31MaxExpress]

Put that 383 in a OBS with a 2,500-3,000 rpm converter and it would be a rocket. So just because it is a Thumper does not mean that it will not perform.

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