The mains got taking out by metal in my current engine. tpi 302 (l99 crank 350 block, its not a ford.) I am tried of running 4.10 gears and I what to go back to 3.42, so I can use the car for cruising. I use the car for half and half driving and draging for fun. I was looking for more bottom torque to pull the taller gears. I am thinking about giving in and building a 350 or high torque low rpm 383. Trying to keep the cost down. Here is the list a parts I have to use.

350 roller block 20 over
Comp Cam 8-302 210/220 480 /480
World s/r heads 1.94/1.5 Manley street flow valves. milled to 64 cc
Ported tpi intake
I already have pm 5.7 rods and a 350 crank.
86 305 injector 19# 39 psi 21# at 47psi.

I'm I better to stay as a 350 with the cam/heads I have now, or build the bottom end as a 383 with a better cam and do heads/intake swap later when I can aford it? If 383, if you swap the rod bolts to the notched apr rods bolts how much grinding do you need to do with the stock pm rods? I know the 383 cranks is about 30 to 50 than to grind the stock 350. I know I need a balancer for the 383 and pistons are 30 to 50 more. Are the injector too small for the 383 if choked by the tpi intake. I have some fuel pressure before they go static. Thanks for your opions. 57Kid should be happy I loosing the 302.

 

the 350 would be cheaper but ur 350 would need larger injectors, the 21s arent gona do.... a good set of 24's would be better. the low duration cam and low CC heads u have are gona make it a low grunt motor with lots of tq and low RPM potential. the 383 will make even more tq than the 350 due to the longer stroke but will limit ur RPm even more with the setup and require at least 24lb injectors but depending on output 30lbs mite be better. the TPI will create alot of tq with either setup but the TPI will run outa steam with the 350 at about 4200-4500 depending on porting 4800-5000. the 383 with a stock tpi will run out at 3800-4000. port it and u mite be get 4200. upgrade the runners and base etc and u'll get more RPM and power outa it without sacrificing tq. the 383 with require new crank, new rods and pistons. dont forget that the setup has to be balanced. so a stroker kit would be required.
383's can be external or internal balanced and requires a 8" balancer. so the 350 would be cheaper for u at the cost of sum tq, but the 350 will wind up alil higher as far as RPM than a 383 with the same intake.

im building a 383 HSR wiht patriot 195cc aluminum heads, compcams XFI280 230/236 .567/.571 lift, 30lb ford SVO injectors, 58mm TB, grannelli maf, 1.6rr, cloyes double roller chain. yadda yadda im hoping for 500hp/tq with a max RPM of 5500-5800. and im running an HSR which flows a butt more than the TPI.

 

I have desktop dyno. I know the tpi power band is 4500 for a 350 and 4000 for a 383. This why I built a 302 because it pushed the power to 5000 to 5500and could flow enough air for the small motor. I plan on upgrading to vortec heads and a new intake later for either engine. I was wondering if it was worth the added exspence to go to 383 while doing the bottom end and using the head I got till I could upgrade heads and intake. I don't know if I can reuse the cam I got anyway. Two of the lobes have some marks from valve float. I was thinking about a hot cam. I was looking info on people that built 383 with weak heads to see how bad the wall was at 4000 rpm. Hot Rod built a 383 back in the day with s/r torquers that had 425 hp. I can still get more fuel out of the injector I got, they don't go static 55 psi. I got 3.08, 3.23 and 3.42 gears to play with.

 

hmm that would be interesting.i didnt think the SRtorquers flowed enough for 425hp.... i mean a set of vortecs would prob peak around 430-450hp. ive seen a few buildups of vortec 383s with carb tho that push 430hp and most crate engines put out 350-430hp with vortecs.

personally more cubes is always gona give u more power. its your choice with wat setup u will ultimitly pick. but i would do it right and do it once. a 383 with a stock TPI will make a ton of torque and will still be fun around town just dont expect to win any races. but downt the road u slap on an intake and new heads and u got a whole diff engine. the hard part would putting a cam in the 383 for the setup u have now and then later to upgrade the heads and intake and then the cam would be missmatched. but u wouldnt also want to throw in a cam now and get it together for it to be a dog untill u can aford new heads/intake.

id go wit the 383. and the 3.08 gears for now, itll make enough torque to get those gears off the line and will keep u in your power band longer.