I've got a 20,000 mile all original Z28 that is in almost perfect condition. It is equipped with the 305 CFI engine. One problem - the engine threw a rod last week.

My question - I am wanting to keep this car as original as possible - therefore I have to keep the CFI intake and injectors - so I need to know what would be the best choice in a replacement engine? Should I go back with just a stock 305 replacement or is there a better alternative (such as a GM crate engine) that would give me a little more performance while still keeping the stock CFI intake and injectors?

 

CFI is sort of the redheaded stepchild of the small block chevy family. If you want to keep it original, the CFI is going to be enough of a restriction that there's not much point in putting a bigger block underneath it.

 

If want more power definately go with a 350, change to bigger injectors cause if you dont you wont get enough fuel, the CFI will bolt on, the ecm might need to be change a little not sure, i do know that some corvettes had Cross fire in the early to mid 80's so an ecm from one might work but i am not for sure you might just be able to use the one you already have good luck with the switch!

 

Our family actually got a 82 z28 crossfire for $160. My brother was doing a swap from a v6 and used several parts off the car so it was worth it. The kid who sold it to us claimed it had a GM Performance parts engine in it. Either way we didn't care as the engine's bottom end was literally destroyed. The motor did have GM Perfomance Parts valve covers, 416 head and a roller cam, I would believe he was telling the truth.

Long story short....

He was proud of the car, and he said he was very content in how fast it ran. Personally i never saw it run, but it looked like it worked well going in and fitting together. I love the Crossfire, its neat and different, I'd go for a performance 305" swap.

 

I know it has been a long while since this post, but I thought you might enjoy the crossfire forum. http://www.crossfire.homeip.net/cftest/startdefault.asp. It is a great site for crossfire info. Don't let people talk too badly about the hp opportunity. A 350 lower end and the crossfire set up will completely bolt up as long as it is a pre 1987 block. Corvettes used the crossfire set up in 1982 and 1984 on the 350 block whereas the 1982 and 1983 Trans Am and Z28 used the 305. They are the exact set up save for some minor runner changes in the 1983/84 versions. I have a ported crossfire intake and ported throttle bodies on a 305 and will be doing a 350 swap in the spring. Currently quite quick and a 350 will make it even better. Roller rockers and some headers, a 350, ported intake, ported throttle bodies and you will have a very quick/fast, emissions legal car that will probably run somewhere in the 15.0 quarter with 3.23 gearing. If you don't go too crazy on the cam, you won't even need to change your ecm and hypertech and a place called DCS even make upgraded chips to consider. DCS is www.crossfireinjection.net.

Spend some time on the site and good luck.

 

I'd get an 87-up short block 350, run an L98 cam with a little port work, TPI fuel pump, and tune a chip for it.

Good performance, mileage, and still looks factory...