I'm porting a set of LT1 heads myself and came across a topic that said not to match the exhaust port with the gasket, but I've already done it.. I didn't make any holes or anything, I'm talking strictly from a performance stand point. I heard that if you make the exhaust ports too big you lose power because the velocity of the exhaust gasses will be too slow and there isn't enough back pressure. I matched my exhaust port to almost the same size as a felpro 1406 gasket. The port still isn't as big as the 1 3/4" primaries of my AS&M headers, so will I be alright???? Any info would be greatly appreciated
Thanx!!!

 

you should be ok

to be safer next time ...don't make exhaust port bigger than Exhaust valve's OD

 

Some people theorize, and I happen to agree, that having your exhaust port be slightly smaller than the opening in your header, provides some small amount of anti-reversion protection.

But I agree with Max...
I don't think you bought yourself any problems by gasket matching.

 

yeah. I guess there's not much I can do accept try it out. I've only done one head so far. Should I do the other head the same way I did this one or should I make the ports smaller???

 

I opened mine up to the same gasket and it makes power,just ran a 12.03 with stock valves and cc305 .

 

That's reassuring.. Nice #'s!! I hope mine can do that

 

Well certainly you'd want the two heads as well matched as possible.

 

The main concern here, is not permitting any mismatch of components (exhaust plumbing or gasket) when assembling. Because is is very possible, actually probable, to not bolt up components exactly centered, it becomes cheap insurance, to have anything assembled to heads, larger than the ports, by amount of possible mismatch, to be safe. As far as anti reversionary notions, sorry, takes more than a 1/32" to matter.

Off topic, but a good comparo; the very reason, bolting a 52 mm. TB to an oem intake manifold, is not a good idea.

 

Can you krazy glue the gasket...

As long as a satisfactory seal is not compromised, let necessity be the mother of invention. Or, improvise, and adapt.

 

Yeah I see what you're saying.