HELP ME DECIDE: UPGRADE 370 to 408?
Oct 18, 2007 | 10:55 AM
#11
The 408 with your 2.8 pulley and bigger crank pulley will likely be about 8-10psi. You'd be able to make more power with less boost and that would be nice. I'd go with compression of around 10:1 though and run a 3" blower pulley to try to keep some of your IAT's down. I'm not sure it'll be worth the cost for the power gain (other than torque), but down the road if you plan to go further you might feel it's worth it.
Unless someone comes up with a really compelling reason I might just upgrade my pistons, springs and cam and stick with the 370...It definately shud be in the 500rwhp range reliably and thats plenty until my wife lets me lose control again...
Oct 18, 2007 | 10:56 AM
#12
Down the road...it wud be nice to take this motor and put into my TBSS! I really do like the idea of 408...but u ever get that feeling that at some point u just gotta go with what u got? Unless someone comes up with a really compelling reason I might just upgrade my pistons, springs and cam and stick with the 370...It definately shud be in the 500rwhp range reliably and thats plenty until my wife lets me lose control again...
Unless someone comes up with a really compelling reason I might just upgrade my pistons, springs and cam and stick with the 370...It definately shud be in the 500rwhp range reliably and thats plenty until my wife lets me lose control again...
Oct 18, 2007 | 12:04 PM
#13
Most would be surprised on the amount of HP you can get out of a 370ci.
Yea a 408 is nice but when running boost with the proper SC or TC you shouldn't see much of a difference.
ON a NA motor i would go 408 because of the increased torque all throughout the band.
Yea a 408 is nice but when running boost with the proper SC or TC you shouldn't see much of a difference.
ON a NA motor i would go 408 because of the increased torque all throughout the band.
Oct 22, 2007 | 08:53 AM
#15
Gonna stick with the what I have...in fact as I'm more involved in the rebuild I've learned a few things...it is only 4.005 bore and I debated going to 4.02 or 4.03 overbore. If after honing, the clearances are too large for the original Diamond pistons, I might up the bore and buy new pistons, but otherwise I don't see any real advantage than for the sake of it...we'll have to wait and see. Also, gonna do a flow test on the heads and make sure the cam and piston dish (4.005 bor/1.162 comp/ -11 vol) match with the heads (AllPro 236/66 - int 2 x3135x4900/ exh 1.6x3130x4915) and compression (9.5). 
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