If your gonna be in there, do the pleanum. You don't want to do all the work just to find the pleanum is leaking, causing some pinging and all the negatives experienced with the plenum. Hughes sells kits for a new plenum plate, it gives you new bolts for both the intake and plenum, new gaskets, and the 1/4 thick amuminum plate to replace the factory steel cap.

 

Sounds good!

So far I've ordered:
Fastman 50mm throttle body
Summit headers
Magnaflow high flow cat (already had super 44 muffler)
1.7 Roller rockers

I'm thinking those things alone should wake this truck up a little! I do have a superchips flashpaq tuner I bought about 2 years ago but never really noticed a difference too much with it. That could be cause my truck was entirely stock but it could be cause superchips blow. I will be ordering my new tuner through hemifever soon!

 

That depends on if there is a puddle. If you take the throttle body off then you'll know for sure unless you have a tiny mirror and a flashlight or a bore scope. You need to see the back of the pan in there since the engine slopes toward the rear.
I mentioned the PCV valve because I thought my plenum was leaking soon after replacing the gasket and it turned out to just be the PCV.

I forgot to mention that one of things I did to my truck was installing a Superchips 3815 tuner and that the gear upgrade is still the best upgrade.

If you had a leaky plenum gasket and put that tuner on the 91 tune then your engine would be ping-city. What tune do you keep it on? Mine has been on the 89 tune for a few years now.

 

I actually don't have any tunes on at the moment and haven't for over a year now. Never really noticed much of a difference at the time but may re-add after doing the mods to see if I notice anything. The only issue is my OBD port doesn't work right. Have to hold the plug at a weird angle for it to work. Do you seem to notice a difference with your tune on?

 

Not to hijack your thread, but...

Are the 1.7 roller rockers pretty plug and play? Take off the old, bolt on the new?

 

Yes, to my knowledge. Harland sharps are one of the few if not the only ones that are plug and play and don't require new springs or pushrods

 

I'd like to pull the plug and do these for the modest gains.

Thanks.




Now, where did I hide that winning lottery ticket....

 

According to the butt-dyno it's a noticeable change in power (enough ponies to notice but not enough to rave about it). It's been a long time since I changed the tune.
When I got the tuner I still hadn't upgraded the gears, installed the airgap or put the roller rockers on so my power was lacking with the 33" tires. I think my truck had the death flash also and a tuner advances the timing to what it should be.

 

Gotcha, I guess I'll slap the superchips back on for now. As for everything else.. I removed the old exhaust manifold, only one broken bolt which from what I've read is pretty good! It didn't break flush with the head fortunately, it broke flush with the manifold so I removed the old manifold and put the new pacesetter shorty's on.. only issue is, the bolts they provided are far too long. Anybody heard of that? It makes no sense.. so I'm going to get some high grade stainless bolts to replace them.. but the new Y pipe and cat is supposed to be in today, so hopefully I can get it all good to go today. Then next weekend will be the plenum gasket and hopefully roller rockers and throttle body but I'll have to play it by ear and see what happens.
​​

 

Might wanna look at doing the timing chain and gears while you are doing the plenum. About 75 bucks in parts. (gear set, and gaskets.) Could change the water pump too...