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Old 08-21-2019, 09:38 AM
BogiesAnnex1 BogiesAnnex1 is online now
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Originally Posted by skinnymike View Post
Thank you techinspector and Bogies. Those ideas add to my info base so I won't get something disappointing. Don't need or want 500 hp or a motor that needs 6000 rpm to run. Just a fun street motor. Thanks.
The performance GMPP Vortec crate motor is rated 330 hp and comes with a roller cam and of course Vortec heads. A good basic choice that with no other mods than adding the LT4HOT cam will grow to 375 to 385 depending on how good your exhaust system is. This is in by 5600 with about 400 pound feet of torque at 3000.

As has been stated earlier the GMPP 290 hp is a SMOG headed long cammed motor with a flat tappet cam, there also is a smaller cammed version at 240 hp that is otherwise identical. I did some cost estimates several years ago which show that the most bang for the buck is to build on the lowly 240 hp version. GM wants a lot of money for the 290 version which except for the cam is identical to the 240. This cam can be had from the aftermarket for about a 100 dollars, so just buying the 240 plus the bigger cam from an aftermarket source puts you a few hundred ahead even if you don't change the heads.

Either of these lower buck GMPP motors will respond to modern heads with better power and lower fuel burn, whether that choice is factory Vortecs or something from the aftermarket. Even inexpensive import heads bring sizeable increases in power with lower fuel burn. The bigger the cam the more staggering the power numbers get with these heads. AFR heads with a cam timing like the Comp XE268H flat tappet or the GMPP LT4HOT roller would easily peak with 400 plus foot pounds at about 3000 and over 400 hp around 5800. These are sizeable numbers from a pretty calm 350. Neither of these cams demand a higher than stock stall converter, they are right at that edge but for street use a factory stall converter works fine.

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