Car is a 1983 Z-28 with the 305 CFI engine. Currently has 114K miles on the engine, and the tranny shifts hard yet. Car is all stock, but will be getting some Hooker 2055's w/ y-pipe, 3" catco cat, and Hooker 3" cat back to help it breath better. I see from reading on here that my first mod should be a full exhaust, and that's what I plan to do first.

So here's the deal, I can pick up a low mileage 350 short block 4 bolt main out of a 1989 Chevy pickup for $100. If I did this I'd throw a Fel-pro gasket kit in it and drop it in. I'd use the stock 305 heads for a slightly higher CR, and use my CFI intake and injection system (after porting the intake while it's out).

My other option is to keep the existing 305 and throw some WP Torquer 305 heads on it, port the intake and throw in a better cam.

1.) which route should I go?
2.) any issues with using the 305 heads on the 350 short block? which head gasket should I buy - 350 or 305?
3.) any fuel issues?
4.) any computer issues?

Car is all stock, but will be getting some Hooker 2055's w/ y-pipe, 3' catco cat, and Hooker 3" cat back to help it breath better. I see from reading on here that my first mod should be a full exhaust, and that's what I plan to do first.

 

Keep the 305 and work on it. You can get the LU5's running pretty good for what they are. The 350 in that truck is complete garbage....the heads, the cam, the pistons, etc.....

 

I don't know, it sounds like an okay plan to me. He'd put the 305 heads on, with their smaller chambers that would bring the compression up nicely. Most likely the truck engine won't have a roller cam, so a good flat tappet set won't be too expensive or cause the CFI too much concern.

 

for a low mileage 4 bolt 350 you'd be stupid to pass it up for 100 bucks even if you didn't use it. Build it as you go when you get it done. Drive that 305 like you stole it and when she goes you'll have a nice 350 waiting.

 

Exactly what im doing now that i have my nice new 4bolt 350 sitting here

 

I have an '88 truck 350 that woke up pretty nicely to a set of 64cc factory iron heads and a hyd roller cam.
The pistons in my engine were dished and the block had hyd roller provisions, but it was originally running a flat tappet cam.
The factory dished pistons have always been undesirable in my book. But if you put some halfway decent heads on there and a hyd roller, it pretty much undoes the bad ju-ju of those icky pistons, and you can get some acceptable performance.
Re use your 305 heads , as five7 suggested, complete with all the mods that you see posted here all the time.
And if you search around, you can find some nice deals on factory roller parts too.
You ought to be able to put together a strong running, reliable engine using that shortblock.
Another plus is that the truck blocks used X rods. They're beefier than the car engine rods.

 

I found out the 350 has ~80K miles on it, and has used semi-synthetic oil throughout its entire life, so it sounds like a good price. It comes with heads, flywheel, harmonic balancer, valve covers and oil pan too. Valley is nice and clean yet, and there's no sludge or carbon buildup.

My current plans are:
'89 Chevy 350 short block
New Fel-pro gasket set
Double roller timing chain
Freshened up 416 casting 305 heads - 1.84" / 1.50" 58cc
New cam and lifters
Ported CFI intake manifold
Hooker 2055's, 3" cat, and 3" Hooker catback

I came across a comp cam specifically made for CFI, TBI and TPI engines. It's comp cams part number 12-249-4 (Grind CS XE249H-12). Any issues with running this cam and lifter kit? The kit is $185 through Summit.

With the 350 short block (dished pistons) and the 58cc heads, what type of CR will I be looking at?

 

I figured my compression to be around 10.47:1. Damn just give up the 100 bucks and buy it. If I was there I would even if I didn't have anything to put it in right now. You know you want to. Just do it. No one will ever know.

 

Personally, any time I have the option of running a roller lifter setup as opposed to flat tappet, I'll take the roller. Because the issue of breaking in the lifters/cam is nonexistent, and in addition to that the lobe profiles are more agressive = more power.
That's a pretty small cam you're looking at. It may not have enough duration for that CR if you calcs are correct.
ZZ4 hyd roller cams are available on ebay all the time for less than $150, and the last time I checked autocenter had lifters for $120 and most of the other stuff to go with that for pretty cheap.
The ZZ4 cam is a good one for mild EFI apps.
http://goautocenter.com/super_deals.htm