View Single Post
Old 03-08-2018, 12:43 PM   #1
ThunderTruck
Registered User
 
Join Date: May 2016
Location: Lakewood, CO
Posts: 8
Need Some Engine Advice - 383 Stroker

I have a '72 2WD C-10 with a very high-strung motor I need to mellow out for better low RPM torque.

I built the 383 years ago (I was 15 and thought I was tough but really just dumb...), and it has always just been way too revvy and boggy in the lower RPMs, and also ridiculously loud to drive.

Here are the basics of the build:
800cfm Edelbrock Thunder series Carb
Weiand Team G Single Plane Intake manifold
World Industries heads with 220cc intake runners, 64 cc combustion chamber - I think it is running 10.5 to 11:1 compression...
Crane Cams Flat tappet hydraulic cam - Advertised Duration 292/302 (Cam Timing 234/244), Valve Lift .488/.510 (with 1.5 rocker ratio)
1.6:1 Roller Rockers
MSD Ignition
Headers with 3" true dual exhaust and LOUD mangaflow? mufflers

I'm running the stock SM465 Muncie with 3.73 posi rear end, and it is just really boggy and hesitant below 3,000 RPM. I have it rev limited at 6,000 but seems like it would rev to 8k if I let it.

Here are my initial thoughts....
1. Run some break-in rockers with a 1.35:1 ratio? Maybe more expensive and difficult than just swapping the cam and keeping the 1.6 rockers, but just throwing it out there.
2. Install a dual plane manifold? Edelbrock makes some affordable options. Maybe keep the single plane and run a restrictor plate?
3. More restrictive/quieter mufflers

I'm trying to avoid swapping the heads and cam but it seems like a cam swap may be my best option. I live at 5,500' altitude so maybe I can get away with the high compression on pump gas. I've re-jetted the carb per Edelbrocks recommendations and it helped a little bit. I can't run the initial timing any less than ~18 degrees without backfiring/flames coming out carb and/or starting issues.

I'm interested to hear any and all thoughts on the easiest and most economic ways to calm this beast down!

Last edited by ThunderTruck; 03-08-2018 at 12:47 PM. Reason: Need to add tags
ThunderTruck is offline   Reply With Quote