I built a similar 9.7:1 Vortec TBI 357 several years ago. And I've been pretty underwhelmed with it. I've got the tune pretty well sorted, but it just doesn't seem to have the power it's supposed to. I've kinda chalked it up to the heavy 5spd.
Keith, I searched your 395 cam and I'm getting:
Duration at 050 inch Lift: 196 int./206 exh
Valve Lift with Factory Rocker Arm Ratio: 0.431 int./0.451 exh.
...which doesn't sound too much different than the LT1 roller cam I stuck in mine.
Fast, GMPP 357 shows:
Camshaft Lift (in.): 0.473” intake / 0.473” exhaust
Camshaft Duration (@.050 in.): 215° intake / 223° exhaust
...so a fair bit more duration and a little more lift. With my stock Vortecs it will definitely need a valvespring change.
Maybe that would be a nice upgrade to try.
BTW Keith, my wife and I vacationed in Australia last year. Brisbane and the beaches for the wife and Port Lincoln with the great whites for me. Best trip I've ever had. We're planning to hit Sydney and Perth next time around for Summernats or Powercrusie. What part are you from?
80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1) sold! for crazy money...but I miss it
94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D) gone but not forgotten
96 Beretta "T56" - 4.8 LS RWD swap / 6spd (0411/2156)
01 Silverado 2500HD - stock Vortec 8.1 / ZF6 6spd (0411/8322)
https://www.youtube.com/c/GEARHEADdezign
F/Y car LT1 cam makes a good bit more power than the 395' cam does. I tried just about everything with my 395' cam to tet it to perform the way I wanted but ultimately to get what I wanted I had to change the cam.
You would not need to change the springs for lift but to reach the rev and power potential of that came it would be a wise thing to do especially if you have some miles on it. Drill out the pushrod holes to 1/2", swap on some LS6 springs and Comp 787 retainers and run some self aligning 1.6 full roller rockers. Would wake it up nicely.
I was recently in my old 350 yet again. Decided to roll new rod and main bearings into it due to an oil starvation/pressure problem I was having. I changed out the oil pump for a stock volume, high pressure 454 pump and corrected my windage tray oversight from the 5 qt pan change. Added a Milodon windage tray. Will let you'll know how it runs once I get the front end rebuilt, again.
Last edited by Fast355; 03-06-2018 at 07:32 AM.
Hi Woody,
I live in Central Queensland just west of Rockhampton.
Just curious as to what throttle body you are running with your set up?
I could get more from my engine if I put a set of Extractors on but I have had endless amounts of trouble with the previous engine trying to keep them sealed so I have made of compromise with standard manifolds but suprisingly still impressed with the proformance.
The only headers I have had an issue with are the cheap ones with thin flanges. A quality header with a flange that is atleast 3/8" thick tends to hold up very well and not leak. The Doug Thorley Tri-Y's on my Express van have been on it 3 years. Never have had a gasket issue with them.
Yep thats great if your vehicle is left hand drive, the range is huge. Sadly these trucks are not that common here and having being converted to right hand drive the steering shaft runs inches from the the right hand head limiting the free space for a quality extractor set up.
Header selection for an Express van is also VERY limited. The ones on my setup are actually for a short bus based on a cutaway van. Very little room to fit headers in there, but Thorley did a great job with execution.
https://www.amazon.com/Doug-Thorley-...rley+bus+heade
I'm running the stock 350 TBI and injectors with the "ultimate" mods at 20psi.
I had Hedman headers at first and they fit great but rusted out after only a couple winters. I put cheap stainless OBX headers on that fit like absolute garbage, but have held up well. I had to cut and re-angle the 4 tubes on the driver side and both collectors.
If you're worried about fitment, just bash em. I was amazed at an episode of Engine Masters where they tested power loss and it basically did not matter at all.
https://www.youtube.com/watch?v=azPKIjxmmdU
80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1) sold! for crazy money...but I miss it
94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D) gone but not forgotten
96 Beretta "T56" - 4.8 LS RWD swap / 6spd (0411/2156)
01 Silverado 2500HD - stock Vortec 8.1 / ZF6 6spd (0411/8322)
https://www.youtube.com/c/GEARHEADdezign
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