Dmm

Hi guys.
Read a LOT of opinions about 906 vs 113, everything has already been discussed in detail 20 years ago. Recently received aluminum 113 heads and zz4 cam from с4 tend to believe that those who say that cast iron 906 is better are right.
My actual build includes 2" tbi, rpm performer intake, 906 head, 705 cam, flat lt1 pistons, 2500 stall 12" tq, 7427 pcm, good idle and vacuum, 36* (not quite right) 3200+ rpm wot, pulls my bubble caprice up to 5200-5400 rpm better than stock tbi with ported 193 heads.
The problem is that I am limited in spare parts and cannot modify 906 heads with threaded studs, spring retainers and beehive springs to put the zz4 camshaft there.
So the question is will I get a performance boost by putting less efficient 113 heads with a more efficient zz4 camshaft instead of 906+705? Some worries about idling.
So far both pairs of heads without any porting, stock 1.94/1.5 valves, stock springs(for 113 not sure) and stock 1.5 rocker arms.
On the scales better flow heads with 200/207 duration 0.447/0.459 lift 117 lobe vs less of flow heads with 208/221 duration 0.474/0.510 lift 112 lobe.

Fast355

iTrader: (2)

No need to put screw in studs for a ZZ4 cam. Comp 787 retainers. 0.050 offset retainer and LS6 springs. You can do that without removing the heads.

I had ZZ4 heads and a ZZ4 cam in the 350 TBI in my G20 van and later put Vortecs, it had a bit more torque and about the same HP with 113s as 906s.

Over the years the Vortecs have really fallen out of favor to me as in I will not spend good money for bad these days. The Vortecs are crack prone garbage compared to even cheap chinese aluminum heads that kick them to the curb power wise.

dmccain

iTrader: (2)

Id rather have the better heads and a lil less cam. Vortecs being the better heads for sure.

Fast355

iTrader: (2)

I do not agree with Vortecs being better. For the typical smog piston 350 in a heavy street vehicle with tall gearing, I would rather have the compression and torque of the 113 heads. The 113s build a good bit more midrange torque than the Vortec heads. You can search the Chevy High Performance Goodwrench 350 build from about 2000.

113 vs Vortec, is similar to the 706/862 or 317 head test Holdener has done on the 6.0L LQ4. The smaller chamber/smaller port/smaller intake valve 5.3L heads stomp the larger chamber, higher flowing 317 heads everywhere under 5,000 rpm. Same thing happens between the 113s and Vortecs.