ok this may be a dumb question but i have searched and searched but cant find a sraight answer...
i have a 89 blazer with the 5.7/350 TBI. im looking at turning it to a 383 stroker with vortec heads etc i was under the assumption it was the LO5 engine that i have in my blazer. started looking more into it and im getting mixed info from people.

is the engine in the 89 blazer a LO5 350 or some other version also what gen is it Gen 1, Gen 2 (LT based), Gen 3 (LS based)??????

 

you have a lo5. the vortec is l31

 

ok thats what i thought thanks. what gen is the LO5? im asking because when looking for vortec heads it ask gen 1 or gen 3 i thought they were interchangeable but apparently not

trying to get around 400hp from it... 383 stroker kit, vortec heads, vortec style intake, 454 tbi w/90lb injectors, 16-18psi fuel pump plus regulator, cam, custom chip, etc etc etc

 

you have the 1st gen. "vortec" name has been around since back in the 80's i believe. TRUE vortec style heads (the good ones) come in 1996+ 350's. they will bolt on your block but the 96+ heads need a vortec intake manifold. (the bolt holes etc are different. Look for the 062 or or 906 heads. (pull the valve covers and look at the casting numbers between the springs. the last 3 digits has to be 062 or 906).

if you buy em used make sure you have them checked at a shop. they like to crack sometimes,especially the 906's,as so ive been told. dont hold me on that one.

 

well i planned on getting a vortec style intake anyway so ill probably use the 96+ heads for a true vortec
thanks for all the info

 

No problem man. keep us updated on how she goes.

 

That goes for the 4.3 vortec also.Since 93to 05 they say vortec which is very misleading.True vortecs 96 up to?