So I have a 93 extended cab with a 4l60e and a 305. I know the older 305’s were “smog” engines made for mpg not performance. From what I have researched these tbi 305’s are no different. Just want to make sure there are no 305 masters in here that know secrets before I throw a 350 in it lol
Hello 2Grim4U,
Good question. I think that a good part of the rule of thumb of the superiority of the 350 vs the 305
is due to how the engine was originally placed in the General's powertrain pecking order. Despite sharing
the same 3.48" stroke, the smaller bore (and lack of 4-bolt mains) cause a lot of engine builders to look
for the bigger brother.
But there's been *lots* of thrilling power built atop 2-bolt main SBCs all the way back to the beginning.
And before you replace your 305, there's a PowerNation video that is a Mythbuster to the inability of the
305 to be built to deliver on the promise. (
Jumping off point over here.)
(The 305 is ~14.7% smaller than the 350, and before watching the video I would have blamed the smaller
bore as making it act even smaller than that on the street...but with modern cylinder heads and associated
21st century technology they made the lowly 305 act a lot more like the fabled DZ302 than a larger yet
smog-headed 350.)
When it comes to overall performance of any system, it's all about identifying the real bottleneck in
the design and
fixing that first, instead of spending money on either side of the bottleneck and
not realizing any appreciable performance gain for all your hard-earned moolah.
Anyway, when you have a little time to make yourself some popcorn, give that video a view and
then sleep on it. (BTW, I was pointed to this video by another member of the forum, and I know
my preconceptions were blown out of the water. Good stuff.)
Enjoy --