Hello from Santa Cruz - K5 Project

Hello All,
Newb here :rockon:

I am joining this forum for assistance in my project of upgrading a TBI 350 (l05?) in a 91 K5 but within California Smog emissions/standards. When I am organized and know where to post I will be looking for these things:

* TBI how/where to start - programs, tuning, etc....
* Confirm long-block build as likely to pass with good TBI tune (hoping to start with the HT383e)
* what exhaust manifolds should I plan on using?
* Anything else I should look at

Thank you in advance!

Welcome! It does suck to have to deal with our smog requirements, but there are things you can do. I'm in Fresno and have a TBI K5 as well (but mine is smog exempt). We'll try to help when you're ready.

Quote:

---

Originally Posted by fastacton

Welcome! It does suck to have to deal with our smog requirements, but there are things you can do. I'm in Fresno and have a TBI K5 as well (but mine is smog exempt). We'll try to help when you're ready.

---

Thank you! I am interested to hear specifics on your K5! Are you part of CK5 and/or Fresno 4WD?

I was a charter member of CK5, but haven't been on the site in a while. Here's a link to mine with some specs: https://warrperformance.com/?page_id=189

All,
I organized my thoughts and will be posting this in the GM EFI section -


I am in the research phase of an engine rebuild/replace for the tired 350 in My K5 - I think it is the L05 - I have ~250,000 miles on the original engine and it is sooooo tired, I just re-gear every other year or so.

My goal - get usable power down low with high(er) torque than the stock 350. This is for a 4x4 that will see dirt, rock crawling, and a bit of street miles with the occasional overland/expedition trips. On the expedition trips it will be towing a small utility trailer (1/4T Military). It will not see the following: high RPM for long periods of time, the dragstrip, or smokey burnouts :)

1. TBI how/where to start - programs, tuning, etc....
   
   • Can I tune the new (383/item 2) adequately and still pass smog?
   • I have another complete TBI setup - build that to better serve the 383 requirements?
   • Please point me to the 'how to tune your TBI' tutorials (software, datalogging). I am PC literate and I have done tunes with systems for Motorcycles, LS's etc… While I understand the components, variables to tune, and data in general I am a NEWB to any TBI technology. (I have had the K5 since 93 and the TBI is like Gump - it just keeps running….)
   
   
2. Confirm long-block build as likely to pass with good TBI tune (hoping to start with the HT383e)
   
   • Will this be a good starting point or will that cam destroy my catalytic converter
   • My requirements for the new engine - more usable power down low. This will rarely see high RPM.
   
   
3. What exhaust manifolds should I plan on using?
   
   • Is there an OEM set I should search for?
   • Is there a CARB set available or will that draw too much attention, legal or not? Something like the Tri-Y for torque - I am not crazy about headers but I hear the stock manifolds on this 350 are very restrictive.
   
   
4. Anything else I should look at?

Vehicle:
1991 K5 - originally sold in Texas (minimal smog equipment: no air pump, plumbing, etc…)

• It has 2 into 1 exhaust before the single cat
• Engine - stock everything
• 4L60 transmission (not 4L60E)
• Gear ratio will be based on 5.13s with 37" tires
• Weight ~7200lb - includes fuel, recovery gear, etc….

Thanks,
Dave