Now that the engine in my blazer is running good I'm planning on the exhaust. Long tubes are a for sure but it's the rest I'm contemplating. The only pre made kits are 2.25 piping. While I've got the skills to build a full exhaust, I don't have the time. So my question is would dual 2.25 be enough for a 383 or do I need to suck it up and have a dual 2.5 built?

 

How much hp is the q? The sq in are as follows. Dual 2.25 is 7.95 as compared to a single 3 is 7.06. Dual 2.5 is 9.82 or +24% over the 2.25's as compared to a 3.5 single at 9.62 and you know that supports a L86 pretty well. If it's a tow motor do the smaller one if it's putting out some power do the 2.5 duals. Hope this helps sir

 

400hp? 425hp? It's not a dragster, need the torque more than anything.

 

I really think you'd be totally fine with 2.25 in the rpm range you'll need it for especially with headers and it won't perform badly at all on the top end. Hell I rarely go above 3k and I've got the bone stock exhaust with blower that's not quite as good as the 2.25 duals but it still ***** and gets when required. Torque is what matters imo it's not a dragster either by any means. However it would help a bit on the top if future upgrades. Not sure if it's worth it imo.

 

when i got my 87 c10 383 it had 3" exhaust it was way to loud i had 2.50 installed that ran all the way out the back true flowmaster's, installed electric cut outs maybe 14ish inches from the collectors thinking the smaller exhaust might hurt when i had it on the dyno open vs closed netted me a whopping 4rwhp so since there was really no differance im pretty sure you would be good with 2.25, the smaller pipes would keep noise down some to and since thats a open rig you might want that

 

I always do 2.5" dual even on stock small blocks.. especially with typical exhaust shop crush bends. You won't lose anything with the bigger pipe.

 

Well after an Amazon gift card and credit card points, I bought a 2.25 dual exhaust with mufflers for $75. Figured what the hell why not. It'll be a bit before the 383 and knowing me I'll change the exhaust three times. Now to save for the headers.

 

You'll be happy with the 2.25".

 

Hope so. Looks like it just delivered today even though they said it wouldn't be until next week and the mufflers that were supposed to ship and deliver with the exhaust aren't going to deliver until next week. Thanks Amazon.

 

And of course summit had 10% off so I just had to buy long tubes.