curtis73 wrote:
My first question is... what 350? Spending $300 to upgrade a TBI engine is like polishing a turd. Spending $300 to upgrade a Vortec or a Smogger is money well spent. I used to build engines for a living. Just ask if you have questions.
I have two 350s at my disposal, though for one 'disposal' is most likely the operative word.
The one that came with the car is a 350 that appears to be a crate motor, if not it's a '79. It had the 624 heads on it (I've got another thread just on heads...), and needed a new rear main due to the Edelbrock carb it came with dumping fuel down the intake. When torn down, I found that it had been bored 80 over and had definite pitting on several cylinders and as such the block itself (and the 80-over pistons; it may have longer connecting rods too) was largely unusable. Did come with an Edelbrock 2701 Performer EPS intake manifold that the 650cfm Edelbrock carb was sitting on.
The second is a '89 TBI 350 out of a K1500 truck. I picked the truck up dirt cheap because both the engine and transmission (a 700R4, mine came with a THM350 and since this will be driven on the highway I wanted the overdrive...) had been rebuilt only a few hundred miles before the truck was hit and salvaged. I've not pulled it out yet, but it appears to be a fairly stock '89 TBI.
I also have access to a '87 305 cheaply, which has 081 casting heads.
The plan at the moment is to build upon the base that this engine & the parts from the other provide- a new cam is pretty much a definite as the TBI trucks apparently had an absolutely worthless one power-wise, I'm looking for better heads (I'd like Vortec heads, but they may not be in the budget unless I come across some either really cheap or in a junkyard), am planning on doing all the mods to the TBI unit to improve it, and hope to get a better manifold. If I use pre-Vortec heads, I have the Edelbrock 2701 that came with the first 350.
The posi you have is probably a clutch-style (not the gov-lock). The springs are very light and they're designed to handle 140 hp from stock wheezer engines of the era. I would actually opt for the gov-lock from the S10. Gov-locks get a bad rap, but in anything less than high-hp drag racing they hold up VERY well. I have a gov-lock behind a 900 lb-ft Duramax that tows 12,000 lbs. The internet talks about gov-locks failing in massive-hp drag racing and all of a sudden it is a weakling that can't handle a 4-banger. 
Correct, the posi I have is a clutch-style, a 3-series carrier 26-spline with 3.41 gears (my memory isn't perfect on the gears though). Don't the S-10's use 28 spline axles though? The G-bodies used 26-spline axles, so I'd need new axles as well...
I did some more checking and updated my build spreadsheet, and I was off by a bit in what I had and hadn't included. Assuming I'm able to sell the K1500 down to $0 or very close to it and taking out what I estimate I'll need for paint and incidentals, if I include and use the current posi rear end, I have $400 for enhancements to the engine.
If I don't use the posi rear end I have, I'd have about $675 for the engine and/or a different rear end approach (the posi rear was $300, but I'd have to FMV the rear sway bar it came with at around $25...).
Suggestions and input as to how to get the most bang for my buck with the engine would definitely be appreciated! 
