i have 227k miles on my 94z71 it runs good but lacks alot of power so end of the year i am looking to get a crate motor looking in summit but the only application i see is a stock rated motor 200hp but i would like something alittle more. any advice?  

If TBI motor still has good oil pressure and not using oil it has a lot of life left. They are not weak motors by nature and respond well to using 89 octane or better fuel and advancing timing from TDC to 8 BTDC. I have one here in a 89 with 185K on it and it runs great. Also if you are running a lift and big tires with stock gears you need new gears more than you need a new engine. BTW, I own a TBI 350 AND a VorTec 350 and the TBI is my favorite of the two as I like its good low and mid RPM torque when properly feed and tuned. I know that with todays fuel prices that one tends to want to buy cheapest fuel but you will find that if you use better octane fuel and advance timing that it will not only run better but be cheaper to drive too because it will improve MPG too. Those TBI motors have 9 to 1 CR and the only way you can run 87 in them is with retarded timing curves which limits true potential and MPG.  

he ain't makin it up! i tried it a while back, just to satisfy my curiosity, and it did wonders. i use strictly 89-90 octane now. it costs like what? 4 or 5 bucks more tank? i get that back in mileage(and then some) plus it's got a little more power. more mpg's and power? i'm all about that, sign my big ayce up.  

YES..I agree too...changed to 89 and now Im getting 85-95 miles the first qtr tank when before I was 50-60 the 1st qtr in town driving.

Hey Sno...Ive never asked and was wondering about my 4.3 V6, you say to advance to 8 BTDC, now is that gonna be the same for my v6 or diff?  

Yes I would try the same setup for starters. A 4.3 is just a 350 minus two cylinders anyway.  

cool...thanks sno. and yes thats a great thing about the 4.3 being a mini version of the 350.  

Also for what it is worth, starting in 94 they also put a internal balancer shaft in them that is driven by cam to smooth engine out more with its uneven firing order.