331 or 347????

[Rick 91GT]

Legendary, you'll make goiod power if you give the 331/347 the parts to feed it properly, the entire top half of the motor and CAM is very important to maximizing a combo.

 

[Legendary]

Cool. I don't know anybody with a 331 stroker so I don't really know any proven combinations. In fear of sounding like a noob I must ask: What is the power potenial with the top half I have already with a 331? (well at least I didn't start a thread about it.)

 

[Nottoofast50]

A 5500rpm converter has no place on the street


Micheal, we made 465/425 to the wheels @ 5800rpm on a very basic blown 331, 9.6:1comp, Cast iron GT-40's, Extrude Honed Cobra, Crane 2031 cam, stock 1.7 rockers shorty headers, 83mm MAF, 75mm TB, 36# inj, 255lph HP pump, full exhaust and cats, all emissons and cold A/C

Sorry to dig up an old thread but i was doing some research on stroker kits.... rick 91gt how much boost where you running to make those numbers?

 

[Rick 91GT]

9.8psi slightly over spinning a A-trim, so the air was hot. We were pretty happy with the results since the combo was fairly simple and emission legal.

 

[Nottoofast50]

Thx for the reply.... i'm going with a similar combo and was hoping for 450rwhp with 12 psi.

 

[1986LX2002]

I have a stock 5.0 block and wanting to make it a 331. Now some people have told me it has to be bored .30 over and other say i can leave it standard bore. Help me out here.

 

[EMW150]

I have a stock 5.0 block and wanting to make it a 331. Now some people have told me it has to be bored .30 over and other say i can leave it standard bore. Help me out here.

It depends on the condition of the block. You could stay standard bore if the bores are perfect but unless the block is new I'd say they're not perfect. Better off to bore it in most cases. A standard bore 3.25 stroke would be like 327 inches.

 

[Legendary]

Gotta dig this up. I came across a friend of a friend that would port my GT-40 iron heads for about 400. Would this port job be good enough for the 331 and keep street driving possible?

 

[Michael Yount]

Not sure how we're gonna know anything at all about the quality/performance of a port job your friend of a friend does.

 

[EMW150]

Gotta dig this up. I came across a friend of a friend that would port my GT-40 iron heads for about 400. Would this port job be good enough for the 331 and keep street driving possible?

As Michael Yount pointed out we can't vouch for the port job but decently ported GT-40 irons should work pretty descent on it for a somewhat mild street build. You'll have to keep compression down a bit from what you could run with aluminum but it should still perfom pretty well. Alot depends on what cam combo, etc. you want to run with it.

 

[Legendary]

Well I just emailed Thumper and asked him about porting them. As long as I can get a good running everyday driving street motor I'll be good.

So running the ported irons I'll have to keep compression down?

 

[EMW150]

Well I just emailed Thumper and asked him about porting them. As long as I can get a good running everyday driving street motor I'll be good.

So running the ported irons I'll have to keep compression down?

I've heard good things about Thumper's work. Run the compression question by him since he has more experience with Iron Heads, he won't steer you wrong. I'm going to say you'll probably want to be under 10.5:1.

 

[mcchargue]

You maybe really pushing it on pump gas at 10.5:1, unless you run the motor pretty cold (160 thermostat). You probably won't be able to run much timing. I am running GT-40P's at about 9.7:1 and they will rattle a little if it get above 185 degrees on 93 octane. They seem to work OK with only 10 degrees initial timing, which helps.