I am debating on using a rebuilt 283 on a 1959 gmc pickup with an sm420 4 speed and 373 gears. I was hoping someone who knows 283's well could tell me what kind of realistic hp/tq i can expect from my current setup. I know everything but the cam. I know it isnt going to be a stock one by the type of rebuild it looks like it will be a mild to traditional 283 cam. Bored .060 over (flat top pistons) 80's 305 h.o. 1.84/1.6 heads 58 cc ( Steel shim head gasket) Performer RPM intake manifold Holly 465 4 barrel carb. Ramhorn exhaust manifolds Thanks in advance
I had that same motor in a stude lark , about 250 to 270 hp , 250 torque,used a copy of the old 097 Chevy cam, but had to change to Z28 springs.them "lil" winders make the hp up high and them lazy 305 springs gave out at about 5000 . They make a roudy "lil" street motor!!!! So have fun .........
I hate to be the naysayer, but I would bet somewhere in the range of 225 hp and maybe 200 torque. Greatest sbc ever built but not gonna pull any stumps. Your combination looks awesome. It's spot on and will be a great little motor.
Have your heads been already converted to 1.6 exhaust valves? I was told by machine shop they couldn't do it, as they would risk water leaks if they went that far. Other than that I think you have a plan. Good luck!
A stock 283 powerpack was 220 Hp With the .060 overbore better heads and intake & carb, at least 250 HP. possibly more.
A 58 power pack was 230hp with overbore and better carb and manifold and cam I think you are around 275hp and 320 torque.
Yes. The 305 H.O. 416# heads have the 1.6 but when i installed them i saw exactly why they wouldnt do much to these 305 heads
You might want to check how much lift these heads will take. I've heard various figures in 305 heads. I've run a Comp 268 High Energy Cam with them and they worked okay. But that was with the open chamber heads on a 350. I've run .442 lift on them before on a 305, that was pretty much stock. That was a Wolverine Cam with 1.6 rockers. It performed quite well, but I never pushed the RPM's that high. I've been told they bottom out around .460 lift, unless the guides are shortened. But like I said before, I've heard several figures on the subject. I've got a .465 lift cam on the shelf with 224 @ 50 degrees, but I'd probably do something with the guides before I installed it. Good luck!
The small cubes and the 305 head ports are not going to play well with the large ports in the Performer RPM intake it will probably be a dog under 2500 RPM and run on the rich side,the standard Performer would be a better match if you want torque on the low end this Weiand intake would also be a better match for torque and port size a guy I know found out the hard way about the RPM intake on a 283 standing behind the car would make your eyes water and it would barely idle. https://www.summitracing.com/parts/wnd-8120/all
Again, its all coming together. this would explain the slightly off intake manifold matchup upon install. I was debating going with an old school cb3 or cb4.
Ran one of these on a 283 back in the 70's https://www.ebay.com/itm/VINTAGE-ED...973825&hash=item215d6c8564:g:5o8AAOSw4x5dCqr9 This wouldn't be a bad match to it. https://www.summitracing.com/parts/lun-10120101lk/overview/
The Jalopy Journal
