What's the difference 305 IROC engine and 305 truck engine?

I have a 1988 Chevy 1/2 pickup with 305 5sp manual. It has over 170,000 miles and getting tired. Instead of rebuilding it, I have a chance to buy a good running 89 Camaro IROC 305 (TBI) engine for $150 (90,000 miles female owned car that lost it's shock tower to rust)

Looking at the parts cost to rebuild, the IROC engine will cost quite a bit more. Probably because the truck engine may be a non-roller engine and the IROC motor is?

Is this the major difference...any other differences??

well they should both be hydrolic roller engines, chevy started doing that in 87. the main difference is going to be the cam and i think the heads and intake. the bottom end however should be identical. although the oil pan from the truck engine may have to be swapped to the camaro engine when its installed.

I agree but I'm pretty sure the truck engines were non roller engines. My S10 motor is from a '90 truck and it's not a roller cam. 4.3's are all roller cams though. I wouldn't be surprised if the heads and intake were the same. I know the heads on 3/4 and 1 ton trucks are different due to valves and seats. For $150 you can't go wrong....

if it actually is an IROC engine, it should be a tpi, not tbi... RS's had tbi's...

The car has IROC-Z written all over it and the TBI looks like a stock setup.

The VIN is 1G1FP21E5KL177XXX

Not a Camaro/Trans Am expert but thought the 1989 IROC had (3) engine options: 305/TPI code F, 350/TPI code 8 and 305/TBI coder E. (Using the 8th VIN digit)

Just checked the following 3rd generation web site..the IROC did have a 305 TBI option in 89

http://www.thirdgen.org/newdesign/tech/techdb.shtml

yup, some IROCs came with the TBI setup.

yup, some IROCs came with the TBI setup.

learn somethin new everyday... i had no idea, i thought all irocs and z28's '86 and up were tpi cars...

I learn somethiong new everyday here, thats why i'm always on here.

Just checked the following 3rd generation web site..the IROC did have a 305 TBI option in 89

http://www.thirdgen.org/newdesign/tech/techdb.shtml
That is surprising, I was almost 100% positive they only has 305 TPI's
Wierd....