Can you help me identify these Twin-H intakes?

[Deleted User]

Howdy-
I was just tinkering in the garage wanting to make some repairs to this Twin-H manifold in the hopes that it would help to sell it. I pulled out my other Twin-H manifold that I intended to keep for my 308 and was shocked to suddenly discover that they are most definitely NOT the same manifold as I had first assumed.

I searched for the casting numbers here but did not find anything. Could you help me correctly identify what I've got here? Thank you!

Here is the manifold I had in storage that I purchased a while back under the impression it was for the 308. Now, side-by-side, I'm not sure that's what its for. The casting number is #5325118

By earthshaker5769 at 2010-10-18

Most of you have probably seen this for sale here lately. I was under the impression this too was for the 308, but again, now I'm not so sure. The casting number is "307093

By earthshaker5769 at 2010-09-27

By earthshaker5769 at 2010-10-18

Is the smaller oxidized intake for a Jet or something? Thanks guys!:unsure:

[Deleted User]

The top one is for the 55 or 56 308 engine. Equalizer built into the manifold. The bottom one is for 51-52- 53 and 54 308's. both can be used on 308 engines but 55 and 56 can only use the top one as shock towers won't let you use the bottom one, no room.

[Deleted User]

Well I'll be. Thanks for the information!
Umm... seeing as how my 308 will not be in a stock configuration, it doesn't make a difference which one I use.
Are the flow capabilities and characteristics the same between the two? I would just assume that the flow of the earlier manifold that has the external equalizer would be better, but maybe the engineering took some leaps and bounds in those few years.
An old racer once told me that Smokey Yunick used to sandblast the interior of his manifolds out to maximize flow. Is this true?
Is one more desirable for some people than others? I imagine if someone had a later 308 and needed a manifold that it would be very frustrating trying to locate one that would work for their application.
Again, thank you for clarifying this.

SuperDave

It's true that the late intake was redesigned for the Nash Body, However.. The exhaust manifold was also redesigned and must be used together. In other words, If you deside to use the 55 intake, you must also use the 55 exhaust.and Vice Versa.. The outlet pipe angle and size are also different than the 48-54.
Smokey said he pumped an abrasive slurry through the intake manifolds to increase size of the runners. Supposedly that would not leave a polished surface which would have been a dead give away that he was cheating. He got his Nick-Name from his smokey motorcycle that he raced as a youth. I think he also blew a little smoke in later years..If you know what I mean.. LOL. There is a process that uses a very thick, putty like substance. I have seen the result of that process and it does not leave the intake runners looking like the original rough casting.It looked like it had been slightly polished. I question how much good that does with an otherwise stock Hudson engine. Breathing is limited in the head and valve pocket design and enlargeing the runners might actually be counter-productive.JMHO

[Deleted User]

Yeah, I also noticed that the later manifold wouldn't mount to the earlier exhaust manifold which threw me.