Early 348 heads 791
- Thread starter Jeffrey Osstyn
- Start date
As Aubrey says to use the heads you have you will also need the matching block, what is the casting number of your block?
Don't know what that is that Ronnie is picking up. He keeps the floor clean so he can roll the the engine cranes and other things around without trouble.
Like to see your Ronnie picture.
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Jeffrey, My apology for not reading your original post more closely. Since your block is already plugged, there is really no reason not to use the 791s, if they are in good shape. I believe the 791 is the head that uses the short reach sparkplug but I'm sure you have noticed that. As for the picture , that is my normal posture, caused by 20+ years of carrying Barry Taylor on my back.
I am glad that someone as notable as Ronnie also missed the part about the plugs. I guess you could use any small port head.
Sorry for jumping in but I have a question for Don, instead of working on the 333, or the 817, is it possible just to add a hp heads, like the 690 or 583 instead of what you replyed of doing with these other heads, and I always wonder why everyone is doing that instead of just replacing the heads? will that work?
There are reasons why some builds use the small port heads as opposed to the 690s and the 583s. One reason is cost. Another is choice of intake.
Assuming cleaned and crack checked, the 791s and the 379s are the least desirable, so they are worth less (but not worthless!).
333s are super common, you can often find them for $100 - $200 a pair (again, crack checked)
The 817s are next up the ladder of desirability, they often run $500 - $600 a pair.
Then we move to the 690s and 583s. If you want big port heads made of iron (not aftermarket) plan on spending $1500 or more for a pair of 690s and a bit more for the 583s. With these latter two sets of big port heads, the builder has a better choice in (mainly aluminum) intakes.
Then there are the 731s (Z-11 heads). Expect to part with upwards of $10K if you were to find them.... And the two piece intake is required and pricey as well.
Not considering aftermarket heads (Bob Walla Racing, McQuillen and the likes of Edelbrock) which are good options for those not concerned with being "factory".
Hope that helps some!
Best, TomK
Assuming cleaned and crack checked, the 791s and the 379s are the least desirable, so they are worth less (but not worthless!).
333s are super common, you can often find them for $100 - $200 a pair (again, crack checked)
The 817s are next up the ladder of desirability, they often run $500 - $600 a pair.
Then we move to the 690s and 583s. If you want big port heads made of iron (not aftermarket) plan on spending $1500 or more for a pair of 690s and a bit more for the 583s. With these latter two sets of big port heads, the builder has a better choice in (mainly aluminum) intakes.
Then there are the 731s (Z-11 heads). Expect to part with upwards of $10K if you were to find them.... And the two piece intake is required and pricey as well.
Not considering aftermarket heads (Bob Walla Racing, McQuillen and the likes of Edelbrock) which are good options for those not concerned with being "factory".
Hope that helps some!
Best, TomK
If your putting 690 or 583 on a 348-380 it cruise around ok but will need no cruising (high) rpm to get the heads to be any advantage over the small port. If that makes sense Carlos.
LOL, thank you, actually It's a truck 409 with 1 notch that I'm thinking of doing a stroker mod, and also thinking of using a M/T 409 stroker crank, but before I commit myself to do this I am trying to get some feedback from very knowledgeable people like your self