GRUMPY I have 327 block that needs rebuilt. Have been wanting 383 for my truck, but was wondering if I could build this instead. Not wanting a hot rod engine, as this will be for my daily driver 92 GMC 4x4. Wanting a bit more torque & hp than stock 190 hp 5.7 that is currently in it, for pulling a trailer over mountain passes.
Id build a 9,5:1 compression ratio 383 and use heads designed for mid rpm torque, and a dual plane intake
use of vortec heads and matching intake, and better valve springs clearanced for a .525 lift would be close to ideal, in this application
http://www.summitracing.com/parts/SUM-151124/
there are 383 rotating assembly's made to fit the small main journal blocks or you can have the standard cranks main journals cut to the smaller diam. OR you can have the blocks man journals bored to the larger size bearings size and notched for the proper bearing tabs
If you decide to get the crank main journals cut to the earlier smaller bearing size,the
bearing size can be cutdown by the larger custom crank suppliers when ordering a rotating assembly, its best to specify exactly what your doing in writing and make a few phone calls along with the written order when doing anything not directly out of a catalog.
the extra stroke and displacement in a 9.5:1 compression 383 will make a very noticeable improvement in the power curve, the cam you select will depend on the rear gear ratio and trans used and if its an auto trans the converter stall speed, and tire diam. etc. so talk with the cam company tech guys ,but Ive built several daily transport truck 383 engines with this cam, as you can see below 400ft lbs of torque and well over 300hp easily out produces a 327 and its off idle power instantly accessible
and it even passes emission testing in most cases.
http://www.cranecams.com/product/cart.p ... il&p=23791
read these threads and sub linked info
viewtopic.php?f=52&t=5078
viewtopic.php?f=44&t=38
viewtopic.php?f=44&t=4462&p=17247&hilit=vortec+400+restrictive#p17247
Id build a 9,5:1 compression ratio 383 and use heads designed for mid rpm torque, and a dual plane intake
use of vortec heads and matching intake, and better valve springs clearanced for a .525 lift would be close to ideal, in this application
http://www.summitracing.com/parts/SUM-151124/
there are 383 rotating assembly's made to fit the small main journal blocks or you can have the standard cranks main journals cut to the smaller diam. OR you can have the blocks man journals bored to the larger size bearings size and notched for the proper bearing tabs
If you decide to get the crank main journals cut to the earlier smaller bearing size,the
bearing size can be cutdown by the larger custom crank suppliers when ordering a rotating assembly, its best to specify exactly what your doing in writing and make a few phone calls along with the written order when doing anything not directly out of a catalog.
the extra stroke and displacement in a 9.5:1 compression 383 will make a very noticeable improvement in the power curve, the cam you select will depend on the rear gear ratio and trans used and if its an auto trans the converter stall speed, and tire diam. etc. so talk with the cam company tech guys ,but Ive built several daily transport truck 383 engines with this cam, as you can see below 400ft lbs of torque and well over 300hp easily out produces a 327 and its off idle power instantly accessible
and it even passes emission testing in most cases.
http://www.cranecams.com/product/cart.p ... il&p=23791
read these threads and sub linked info
viewtopic.php?f=52&t=5078
viewtopic.php?f=44&t=38
viewtopic.php?f=44&t=4462&p=17247&hilit=vortec+400+restrictive#p17247