[HIGHRPM]

HI GUYS. I just picked up two 86 iroc 305 's for next to nothing. I know some people say this motor is no good, yet some say it's great. I plan on doing a mild/strong daily driver for my 2 - 260's and would like to hear from everyone that runs this motor on what parts and combos that they used, what works and what doesn't. I was thinking about vortec heads to improve the air flow plus the normal cam etc. So, all help would be very appreciated.

ROD

 

[Tyson(280z)]

Re: IROC 305 BUILDUP

I dont know much about v8s yet, so dont go by just my word, but that 305 will spank a stock L6 Z any day.

For a mild/strong daily driver I wouldnt see any problems. You got the motors for dirt cheap, might as well use em.

 

[Chuckz Z]

Re: IROC 305 BUILDUP

my father and i just built a 1938 buick, we turned it into a Hot rod. The car came with a 454, we took it out and put a 305 ho in it out of a z28. If this engine has fuel injection, it can be tricky. Chevy started what they called Cross fire fuel injection, it is @!#$. We put a 650 holly on. ANyways, we built this engine up with a rpm intake, titanium valves, a wild cam, and ported heads. This car does 0-60 in
5 seconds. That is all steel let me remind you. SO you can do ANYTHING with that engine, just remember that you are putting it in a car with weaker frame, and you can twist your car in half. SO dont put a built up 305 in your z unless you do some frame work.

 

[yo2001]

Re: IROC 305 BUILDUP

305 is nothing in Camaro. May be good for Z. It would beat stock Z. I beat one in my mod Z. we were dead even to 70mph. Then I shifted to 3rd and I beat him by a bumper. I like 350 better. 305 is like weak 350.

 

[Tony D]

Gawd help me, but I can't resist!

My first temptation is to say "put a Predator on it" BWAHAHAHAHAHAHAHAHA!

Now, that being said...
I had a 77 Impala with a 305. I put Corvette heads and Distributor, along with a stock GM Four barrel manifold and quadrajet on it. Ran like a raped ape! I would skip all the trick high-dollar parts and stick to some well thought-out junkyard swaps. The 305 is as maligned as the 307 of earlier years, but is STILL A SMALL BLOCK CHEVY!
There are TONS of parts for it, and you can make it respectable looking, with decent power. Fact is, the 305 is probably a better choice than the 350 as the power is a bit more tractable.
My suggestion: keep it stock until you get the quirks of the conversion worked out and see how you like the car. If you need more speed, THEN go for the mods.
Otherwise, do the things that reduce the mill's weight: small atarter, aluminum flywheel, intake, steel-tube headers, etc. Anything you put on the 305 will fit the 350, so it's transferrable if you "go bigger" later on!
If you have a 305 with the TPI, KEEP IT! There are stand-alone harnesses (Arizona Speed And Marine comes to mind) that allow this swap EASILY! Fuel injection kicks Carburetion any day of the week.

Unless you have a Predator, then all fall by the wayside in awe of your performance. (Again, the drink prevents my restraint of smartass coments--forgive me!)

 

[SpeedRacer]

Rod, The 305 SBC got a bit of a bad name because back in the "emission/fuel economy" days because Chevy built some of them with 76cc heads and dished pistons so they had no compression (something like 7.8:1) and therefore no HP or torque.

As Tony D says - it's a small block Chevy - loads of go fast goodies. There isn't a "bad" small block.

Stop over at Hybrid Z http://www.hybridz.org/ for some additional help. BTW, there is even a manual from "Jags That Run" http://www.jagsthatrun.com/Pages/Datsun_Z_V-8.html to help with the conversion.

If you are interested, here are a couple of shots of my 1971 240Z based 1962 Ferrari 250 GTO kit car with a 327 SBC in it http://albums.photopoint.com/j/AlbumIndex?u=1743399&a=13418353&f=0

Good luck!