305 to 350 swap

[TexasRed]

I'm trying to start to piece my 350 together again to replace a 305. I have vortec heads and I understand that 305's have different  exhaust manifolds than 350's and other small blocks of the chevy variety. Last time I was at LKQ I saw some manifolds on a 74 monte carlo that had the air tubes (it was a california car) with a crate 350. I don't see air tubes in any manifolds except the 305 trucks so I figure I may take them. I planned on doing the edelbrock header thing but my money's gotten a little tighter and stock manifolds (with my porting) may get me down the road more and I can always do it later. I'd prefer to save the money for better piston ring combos and bottom end parts. Some of you have done the swap, so do 305 manifolds swap over or no or should I get my tools and go?

[eventhorizon66]

It may not help you with this question, but if you are about to start building your own engine (even if it isn't your first), I would check into picking up a copy of this book.  David Vizard has to be some sort of genius.  If I had read this book prior to buying my current crate engine, I would have most certainly built/blueprinted my own engine.

[Dragon]

The Exhaust Manifolds interchange between the 305's and 350's, you just want to check them out and make sure they will ft your truck(Should be fine, but check the passengers side as it might have Frame rail issues, if it has the right angle to it)....

[TexasRed]

Yeah eventhorizon, I got that book.  . That's where I got the idea of porting the manifolds. Although, I was kind of annoyed with Monsieur Vizard going to mechanical secondary carbs after the second or third engine buildup. I mean, he advocates vacuum secondaries for a street vehicle and then comes out with combos with mechanical secondaries.    I'll probably end up having a shop build my short block, or perhaps even long block. I don't have time or space to be doing it.

I thought the manifolds were different: http://www.hotrodders.com/forum/350-exhaust-manifold-116869.html

It talks about the late 70's but maybe it's different for my 1984. It would be great if they did interchange, so I can just forgo doing anything about it until I pull the old engine out, I can pull it complete with manifolds and port them.

Thanks guys for your help.

[dumbucket1]

just for reference my 84 blazer had a 305. 267, 350, and another 305 in that order in it and I used the same manifolds and exhaust system with every motor.