posted thsi on engine board too.

[cheyenne10]

I've got a 72 3/4 ton 4x4 suburban. I now have a new GM goodwrench 350 motor in it. I have an
older TH350/NP205 setup with 4.10 gearing and LT235/85/16 tires. This thing doesn't seem to have
all the pickup and power I would like. My assumption is that it is under powered for a big rig. If I wanted to get this unit to get up and go where should I put my money?

Lately I have thought about

#1 buying a crate 383 with 325HP/415 FPT and using 350 in a 2 wheeler 1/2 ton.

#2 changing out exhaust and living with it (I have not replaced old 2" single exhaust yet and do not like headers. I hate to add 2.5" dual exhaust and then want to put a 402 BB in it later with more mods.)

#3 Put in a 396/402 by moving engine forward to clear firewall.

#4 Some type of mods to 350 I have.

Lets here your suggestions and guesses on costs!!

[dtlilly]

A correct cam and intake set-up on your 350 might help. A higher stall converter and tranny hop might help also.

[1969 GMC]

Assuming that a complete blower setup is cheaper than a crate 383, trying supercharging on for size

[JimKshortstep4x4]

Since your Burb is around 6,000 lbs., the engine has some
serious weight to move! Not sure what you mean by underpowered but I would lean toward dtlilly's ideas. I would add heads to the list and the duals. With 4:10 gears a good 350 should do pretty well. No dragster though!

Jim

[cheyenne10]

Thanks for all the good suggestions so far. I do not want to turbo charge this beast!! I guess the GM motor might not have the best cam for my application but I assume it has near stock specs for all of our trucks. I think I will try the new exhaust route and then go from there. Does anyone knwo what mods need to be done to exhaust when SB is replaced by BB? Using a 2 1/2" system I think that would work for both.

Does anyone have any 4x4 experience with the 383 motor? Source for crate one?

[714x4lover]

i just put a 383 stroker motor im my 71 chevy 3/4 ton 4x4 longbed it weighs 5600 lbs i wish it could have more power than it has but it moves the truck like you wouldnt believe i think a set of camel hump heads, maybe another 50 or so hp, i have right around 400hp and 425 torque i had done to mine 350 4 bolt main, bored 30 over stock heads with port and polish job, chrome moly rings, high output oilpump,iski cam better than rv cam, i also i used 5.7"connecting rods, edelbrock rpm intake,edelbrock 750cfm carb, heads have stainless valves,heavy duty springs, i've also done the exhaust i used 2 1/4" pipes with dual flowmasters, if you use any bigger pipe than 2 1/2" you'll lose alot of torque i also used block hugger headers, im not really impressed w/ the headers i might go back w/ stock exhaust manifolds, but then again the stockmanifolds passinger side likes to break while your 4 wheeling so i thing ill stay w/some sort of headers any ways you can do to you engine you have now might save u a few bucks now but you'll have to take the motor out to work on it . you can put in a good cam, a set of heads is where you 'll get your most power(a good set is 202 chambered w/ some kind of roller rockers, if you get a high lift cam dont forget the hd head springs) a dual exhaust systemw/ a muffler that has good flow, no bigger than 2 1/2" pipes,headers wont hurt you will get arount 13 to 15 more hp every horse counts right. you can also put a hei distributor w/ high output moudule,coil and advanced curve and spring set msd has a good setup,or you can buy the whole distributor for 275, buying the extra componants is cheaper way to go. intake and carb holley or edelbrock works well, dont forget a good aircleaner k&n has one you can clean and reuse. oh a good double roller timing chain.