1991 K5 Blazer 350 TBI Vortec Head Swap Done, Truck Running, Part 3

Finally Done with the Vortec Head Swap. I had to swap out the first set of heads due to one of the heads having a freeze crack in it. I don't know how the machine shop didn't find the crack in the head. I avoided the machine shop this time, and just slapped some 062 Vortec heads from a cash for clunkers Suburban. Truck runs ok, but motor bogs down when giving it gas. The ECM needs a tune, and it needs bigger injectors and a bigger throttle body.

Category:

Autos & Vehicles

Tags:

• 350 Engine
• TBI
• Vortec Head Swap
• Chevrolet
• Chevy
• Cracked Cylinder Head
• Coolant System Pressure Test

[OSDCrusher]

Do you still have the truck?

[civicboy123]

@OSDCrusher I sold this truck last summer. It was a sweet ride!

[mrhangfire1]

Did a similar swap in 2005 with 383, vortec heads, lunati voodoo cam, custom 750cfm TB w/ adj. regulator and GMPP intake. The main problem is that the TV cable to the tranny is very finiky and the bolt pattern on the intake will not facilitate the original bracket. You have to make one or smoke the tranny(700r4) I think it was TBIchips.com that would burn custom chips for these using the WinALDL software but I had to convert DB9 serial to USB for data logging.

[civicboy123]

@mrhangfire1 I had to modify the original TV cable on the engine. I got it working perfectly! There is a guy locally that burnt me a custon chip for this truck. We spent an afternoon last summer data logging the truck, and then he would burn a chip and we drove it to see how it felt. It took about 2 tries, but he nailed it dead on. This guy is local, and has all the stuff to burn custon chips, and is very good at what he does. I does this on the side, and is a great guy to use if local.

[hiimconrad]

Hey I just did this to my truck I got it running also running rich I didn't change the cam. It has no power at low rpm ! I was wondering what is your timing advance on the dizzy and where did u end up getting ur injectors from and of I should chipp it or no gains ?

[bigpaw64]

@civicboy123 hi--im not sure what you mean by peanut cam?--if your refuring to mine--its a crane cam in my engine-just a bit more lift over stock--not to mess with the computer. i was wondering if your running a carb intake w/adapter or the gmpp tbi vortec intake???-----thanks for the reply-------do you still have the truck???-----looks like it runs well----------Don

[civicboy123]

@bigpaw64 If your going too do this swap I would suggest getting rid of the peanut cam. You need something that is going to be computer friendly with no too much lift. The vortec heads will make this engine breath, and it will runs good once its done right. Regarding the egr valve just block off the hose going to it. Mine never threw a check engine light or code 23. I your going to go with a big radical cam your going to need to go with a 454 throttle body, injectors, and a custom tune.

[bigpaw64]

@civicboy123 hi-im about to do this exact same job on my 90 blazer-----i have headers on mine so i dont know what to do with the egr valve--also----i wanted to know what casting number on your intake???----i bought the new tbi vortec intake from gmpp---i hope it works as well as yours----thanks Don

[patches1223]

@94civiclxgrey thats what hes eventually gunna do but for now only heads he has are 305s

[94civiclxgrey]

@patches1223 Brings up his compression ratio for hp gain it has pros and cons though better off using vortec heads and different pistons but that costs more than a set of 305 heads lol.