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850 Demon vs. 750 Holley 3310

Posted By: Anonymous

850 Demon vs. 750 Holley 3310 - 06/30/11 03:56 AM

The motor is a 77 440 with 9:1 compression, early 906 heads (milled a little to get the CR where it's at), a cast iron intake, .484 MP hydraulic, Hedman headers, MSD 6AL, 2,800 stall convertor, 3.55 gears, blah, blah....

Very mild build.

The intake will be replaced by Holley Street Dominator when I find a good used one.

I have the two carbs at my disposal and have always been happy running the 750 3310 on other similar combos. My experiance has been very good drivability and power for mild combo's.

Will the 850 Demon be too much?
Posted By: joedust451

Re: 850 Demon vs. 750 Holley 3310 - 06/30/11 06:52 AM

Quote:

The motor is a 77 440 with 9:1 compression, early 906 heads (milled a little to get the CR where it's at), a cast iron intake, .484 MP hydraulic, Hedman headers, MSD 6AL, 2,800 stall convertor, 3.55 gears, blah, blah....

Very mild build.

The intake will be replaced by Holley Street Dominator when I find a good used one.

I have the two carbs at my disposal and have always been happy running the 750 3310 on other similar combos. My experiance has been very good drivability and power for mild combo's.

Will the 850 Demon be too much?




I'm sure the 850 will be much, not enough stall & gears & especially if its a Mighty demon, I'd run the 750 3310 on a set-up like that sence you already have it.

Now on the compression, are these factory pistons? even if you mill those 906s alot i'll bet your not at 9.1 with the stock pistons, how much were they milled? The factory pistons on a 77 440 are a good .180" in the hole, the true compression is no higher then 7.8.1, the earlier blocks (68-71) had the pistons .080 in the hole, the compression on them were around 8.7.1, thats having the pistons .100" diffence between them, the pistons will have more affect in the compression on the placement of height then milling the heads the same amount. I milled a set of 452s on a 77 446 i had .050" & it raised the compression not even 1/2 point, so i was around 8.3.1 tops, The engine ran about the same, when the pistons are that far down its really hard to make a big difference in noticable power just milling the heads, but if you install a set of FTs higher up it makes a big differance, Going with a set .020" below deck is night & day. But if you have aftermaket pistons then scratch what i just said.
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