When I bought my IROC about 1 year ago the people who i bought it from was selling it as a 350 when the VIN says its a 305. Anyways I used this as a barganing tool and got the car $1000 cheaper than what they were asking. I got to thinking today.....mayde someone really did switch out the engines at some point to a 350. I've never ridden in a 350 iroc so i dont know how the power of a 350 compares to a 305. So my question is, how do I find out how big my engine is? The engine code should tell me this but I dont know where it is located on the block. If anyone could tell me where the code is located or any other way of finding out the true size of my engine I would greatly appreciate it.

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> 1990 IROC-Z (black)
> one of 3000 IROCs with a 305 made in 1990
> flowmaster exhaust
system with mufler bypass
> z-28 spoiler
> blue under car neon kit
> check out my site at: http://geocities.com/thickfacek/IROC-Z.html

> email me at thickfacek@nc.rr.com

 

I dont know if you can see it with the engine in, but the last engine i sold said something like "GM 5.7 liter" on the back of the engine (near where it bolts up to the tranny) behind the driver's side valve cover.
good luck

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*1989 RS
*Red, Daytona Turbo fiberglass hood, chrome 16x8 IROC wheels
*355 CID
*TPI ported plenum, SLP siamesed runners, Edelbrock high flow intake
*Edelbrock TES Headers (getting SLP 1 3/4 this summer)
*Richmond 3.73, Auburn Posi
*Modded 700-R4, 2800 stall converter
*NO recent time slips.

 

On the passenger side there is a hog that sticks out and info is stamped into it. it is usually impossible to read without a scientifiv evaluation. But it is a place to start.

I was told that the harmonic balancers on a 305 is a different size than the 350's too.

The easiest way might be to look at the heads, if they are factory. the casting number can be seen on the side by the exhaust manifold (If I remember correctly.

John