408 little low on power
probly won't go that far..this is a street/strip car,figured 12.5-1 was to the edge of running race fuel..with 12.5-1 do you think afr 225 heads will flow enough or needs to be cut and opened up with what cam I have.
probly won't go that far..this is a street/strip car,figured 12.5-1 was to the edge of running race fuel..with 12.5-1 do you think afr 225 heads will flow enough or needs to be cut and opened up with what cam I have.
You could also add Meth injection if your car doesn't like summer months (on premium pump gas).....E85 would fix any problem with octane at your compression...

AFR 225's work really well on 40X engines. I like there bigger heads on 42X-45X. The extra flow of the bigger heads and cubes really should require a great SP manifold to get every last ounce of power. I know my heads will be choked with a FAST and that's why I ordered my porting with smaller intake CC. Yeah, I give up 15-20 cfm @ .7 lift. But I'm not going that high lift anyway + Ported LS7 FAST only flows like 310 CFM MAX. You'll be fine with the 225's. With E85 on board you should easily go over 550. That's just a number anyway, but as long as you dyno at the same place you'll get a good handle on how much you gain. That cam you have will like the extra comp and should really show big gains in the TQ area.
One more thing. Advance your cam to 4 degrees total with that cam (108 ICl). That late abdc of that cam does not go well with stock or Fast intake. It may not show up as a double tq bump at the dyno but it will drop your low to mid range tq. That cam on a 408 has more than enough ability to go well past 7200rpm (most hyd lifters and springs don't like it much past this rpm anyway) so why not put your useable range down to below 7200....A ported FAST will generally peak at 6400-6500 on a 408 cube engine.
Last edited by jimbob; Mar 28, 2011 at 05:05 PM.
You could also add Meth injection if your car doesn't like summer months (on premium pump gas).....E85 would fix any problem with octane at your compression...

AFR 225's work really well on 40X engines. I like there bigger heads on 42X-45X. The extra flow of the bigger heads and cubes really should require a great SP manifold to get every last ounce of power. I know my heads will be choked with a FAST and that's why I ordered my porting with smaller intake CC. Yeah, I give up 15-20 cfm @ .7 lift. But I'm not going that high lift anyway + Ported LS7 FAST only flows like 310 CFM MAX. You'll be fine with the 225's. With E85 on board you should easily go over 550. That's just a number anyway, but as long as you dyno at the same place you'll get a good handle on how much you gain. That cam you have will like the extra comp and should really show big gains in the TQ area.
One more thing. Advance your cam to 4 degrees total with that cam (108 ICl). That late abdc of that cam does not go well with stock or Fast intake. It may not show up as a double tq bump at the dyno but it will drop your low to mid range tq. That cam on a 408 has more than enough ability to go well past 7200rpm (most hyd lifters and springs don't like it much past this rpm anyway) so why not put your useable range down to below 7200....A ported FAST will generally peak at 6400-6500 on a 408 cube engine.






