I've recently purchased a used L98 off of a 89 IROC. It's going to take some time to finish the 350 build so in the mean time I was thinking of cleaning up the 083 heads and see how the L69 responds.

My first inclination is that the compression will be lower and, if anything lower the performance of the engine.... But yet, I'm quite curious of just trying it out.

Also, going to have Hooker 2055's bolted in as well.

Anybody try the same thing ?

 

More flow means more fuel you will need to tune it lol, but you should see an increase with the right compensation.

 

So when you say tune to compensate for the compression .... What exactly would you recommend?

 

It's simple really fuel and air mixture is all you need to compensate for the compression, which isn't an issue in the first place it's just what you read off the internet.

 

How is anyone supposed to have better heads if they worry about this ****? The 305 can make some hp with a cam, heads, and intake. I tell anyone it all starts with the heads that's the main course. Then worry about the cam and intake.

 

The L69 416 heads are good. I've seen 416 heads do 12's with a 305, mainly because it had high enough compression to handle a big cam. Dropping the compression via 083's is the wrong way to go. From what I understand the 081's are the same as the 416's, just they're the centerbolt version of that casting. The 083's are supposed to be the same as the 081's, just with a larger combustion chamber. the flowrates for each of these heads is pretty similar from what I understand. The differences are in valve sizes.

Also, 416 heads were used on LG4's also, but those were slow pigs because they were low compression engines.

If you insist on trying it, go ahead. It might be interesting to know for sure. But I think it will be a net loss.

 

Agreed lots of work to make it less powerful theres better ways to spend money and time imo.

 

It's going to be a long, cold winter....and work will probably be slow... Time is not much if an issue and money spent will be minimal. If I can get my garage heated enough, I might just be crazy enough to try this