See, Here is your recipe!This is the best data of all; realworld.
10.1/8.8/.029Quench/185psi/91gas/28&20timing
So let's run that 280H. I found this cam; 10-204-4 with 280/280/110/230/230 &490/490lift Thats a lot of cam for a street teener but here goes.
If you install it at 106, the ICA will be around 66*. Using a bore of 3.94,stroke of 3.31,rod of 6.123, This cam wants an SCR of 10.5 for a Dcr of 8.23 and 166psi.This is what typically burns 93 with a tight Q.To get a 10.5 Scr you need 69.6cc total chamber volume.
Anybody see a problem here?
Ok lets say the heads do come in at 59, and the gasket is 8.9 and the eyebrows are 5 and say the pistons are down .010=2cc. Ok; 59+8.9+5+2=74.9cc Winner we have a dog-motor!
Well not really, the Scr works out to 9.8, and the Dcr to 7.7/152psi. So it will have a hole, need a big TC, and gears and suck gas pretty good around town, exactly wrong for a streeter.
In this case you would need to eliminate 5.3cc to be rocking. Well there are 2 in the deck height, which are very expensive to buy. But you could go from the .039 gasket to an .028 and get 2.5cc there. Your Q would be better at .038, and the compressions would climb to 10.13/7.95/159psi. And that is much better.
But really that cam is 230@050, kindof way too big, IMO,for a street-teener.And it's a single pattern cam.
Now, if you would be willing to to go down to say a 270 cam and install it at 108 the ICA might come in at 63* and then that 9.8 engine would get you a Dcr of 7.9@157psi. This is still a pretty big cam for a teener.
With the 10.13 engine this would be Scr of 8.14@164, yummy!
And if you would consider a 262 cam and the 10.13Scr, you could get you an ICA of 61*, and a Dcr of 8.25@166psi. This is dynomite! This will boil your 275s a good long ways.It will get fabulous mileage. It can use the stock 2200ish TC, with 3.55s.If you need a lil more Giddy-up, a 2800TC will really wake it up, and that 2800 might work pretty good with 3.23s if they are already in there.
So to recap, this is pistons down .010, the .028 gasket, and 59cc heads.
Now I'm not telling you to run the 262 cam. I'm just having fun with math....... You can change the parameters any way you want to run almost any street cam, some combos just look better on paper. Measure,measure,measure. That's the difference between a Fantastic engine, and an also-ran.
>Pressures over 165 usually need 89 to 91 gas under load. But with a TightQ , moparofficial says he runs 185. I can't say one way or another, and to you it doesn't matter, cuz your heads are chosen, and there is no way to get your total chamber volume down low enough to get that much pressure with any performance cam.Well there is but that would take custom pistons.
As for me, I'm liking the 270 with a 2800 and 3.73s
If it helps any, I have run a totally stock low-C teener long block with a 2800,3.55s,the 2.74low A999, headers, and a TQ,in a 3650 chassis, and I had a lot of fun with that. Almost as much as when I ran it with 4.30s and a 4-speed. Actually I think I mighta had more fun with the automatic.