okay, but the motor still felt like had a serious lack of power with only 30 inc tires moundted, is it possible for transmission to so bad that it is not transfering powerefficetnly cuz my 700r4 isnt running great seeing as to how i got it from a junkyard im not surprised i just hope it keeps the truck moving until i have enoudh money saved up for a bulletproof rebuild!  

recheck your valves, you can adjust em while it running, it's messy if ya don't have clips or cutout valve covers,

loosen em one at a time till they clatter then tighten em till they just stop then another 3/4 turn.

that'll put em within range of being correct.

too tight will rob ya of alot of power and it's very easy to do when ya don't mess with em all the time.  

Geo450racer:
okay, but the motor still felt like had a serious lack of power with only 30 inc tires moundted, is it possible for transmission to so bad that it is not transfering powerefficetnly cuz my 700r4 is running great seeing as to how i got it from a junkyard im not surprised i just hope it keeps the truck moving until i have enoudh money saved up for a bulletproof rebuild!

You might start with doing a vacuum check on engine to see what you are pulling at a idle to get a idea of engine health and timing overall before you start thinking about tranny. .  

hey geo, try the compression test. maybe your bottom end is just tired. also check the book to make sure your timing is correct. at 0 degrees, the lip on your coil (HEI) should be pointing to the right (drivers) side of the truck.

also make sure your firing order and distributor position is correct. if you drop the dist in a little off, it will run crappy, but still run with a twist of the dist. make sure you're on tdc at #1 piston, and the dist goes in with #1 dist cap tip in a line with the #1 cyl. haynes manual (67-87 chevy trucks) has a good picture of what i'm trying to say.

clockwise 18436572

try timing it with the vacuum advance on and also off, and then reconnect it, etc. try different stuff with timing light and test drives until you think it feels perfect throughout the entire rpm range. some guys time a truck without a light at all, just trial and error, and what runs good.

get a spray bottle with water at night and spray your plug wires to see if ther is an arc anywhere, that will make you lose power, too. sometimes spark plugs get half cracked during an install, but they still work half of the time. especially if you have hedders and you try to install plugs with a socket, you have to go crooked with the socket in some cylinders and risk cracking a plug. so it may run crappy because of that, too. if you have hedders, just use a 5/8 wrench to install spark plugs. also make sure your spark plugs have tight tips on them. some manufacturers have the screw on tips that come loose like bosch or accel plugs.

check the tips on your cap. i bought a borg/warner cap from a local auto parts store last month, and 2 of the tips cam loose after 2 days of driving.

check the spring action in your distributor, and possibly spray with penetrating oil if you live in a moist climate. sometimes a spring will break and you lose your advance. there's also an advance modulator in the distributor. it looks like a little half moon thing with some wires hooked to it under the dist cap. sometimes those go bad.

if your vacuum advance hose is old an thin, and worn by engine heat, it may be sucking itself closed.

also try running a #140003 (accel part number) coil. it's a hotter coil and it helps to burn the cheap gas better. most of my buddies run that accel coil and we have all seen noticeable improvements.(especially on older engines) just make sure you have at least 8mm wires or they burn up quick. the little wires split like a ball park frank when you run a hotter coil.

if you dont think you're getting enough fuel, try a corvette fuel pump from a 350 in the 70's. they will push a little more fuel than a regular OEM mechanical fuel pump, and they bolt right up. but they're 25 bucks instead of 7 or 8. cheaper than an expensive holley electrical pump that cant handle mud or water or a bump in the road.

new fuel filter, good gas etc. i'm sure you have already done most of those little things. keep trying, you'll get it running good. good luck!  

wow thanks for all the advice, im gonna get around to checking compression tommorow and i probabley did overtighten valves so ill try the hearing method of adjusting valves but as far as timing goes im pretty sure its all correct, i might even try the 8-10 degree advance for a little bit to see what it does but im really sure that ive got a bad bottem end cuz a 350 should be at least able to spin 30 inc tires, also i already have the accel coil and plug wire, im running bosch plugs  

so i did the compression test and am sad to say that ive only got 100 psi of commpression but on a good note the motor is actually a 4 bolt main and is made in mexico like mud said it was.  SO now what do i do? ive decided to stick to small block so should i stuff some flat top pistons and hot cam in it or build a 383 stroker with flat top pistons and hot cam , i plan on reusing my fresh heads since they are like only 2 weeks old since the machine shop rebuilt them, how much cost am i looking at for a bottem end rebuild on 350 vs 383 ?  

don't just try 8-10.. thats where it needs to be...

as for the hot coil,
it won't help, it also won't bake the wires.

the modulator thingy with wires is a pick up coil, not an advance mechanism. there is only a centrifugal advance, (the springs and weights under the rotor), and vacuum in the era of the vehicle in question.

and for setting the timming with the vacuum advance attached... dude what are you smokin? cause i need some of that. it will really run like crap if it's getting enough vacuum to advance the timming while yer setting it.

o...
an it makes no difference in any shape or form where the distributor is pointing, as long as the #1 wire is on the terminal thats being pointed at while at TDC of the #1 cylinder. the only problem you'll run into is with fitted wires a couple wires won't wanna reach the terminal.

the flat top pistons and your new rebuilt heads will run very well in the form of a 383 with a advetised 260 duration cam. getting a hot cam isn't gonna make ya happy or spin your tires either.

even with the compression on the low side you should be able to make it run strong properly tuned.  

Actually in the old days, we timed it by ear and vacuum gauge and it works really well on some engine if you know what you are really doing. Not really possible on a newer engine with computer controlled spark thought.  As far as CR, if you have 100 PSI cranking compression you need to do a wet test too to see if it is rings of valves. If it does not come up and you are sure valves are good then you have either and radical cam, valves preloaded too tight or cam out of time. Not engine is going to run well and strongly with 100 PSI cranking compression no matter what the tune. (unless it is from a radical cam then it will run well at high RPM's) you need to find the cause of lower compression before you go further because it plays well with your lack of power feeling too.  

wow all this stuff i didn't know!, well to tell you the truth i just opened up the timing book, so im not a pro but i will do the tuning you guys are talking about and no i don't have radical cam in it  

well i finally got around to messsing with timing, this time with vaccum advance off, and i advanced timing to 6 degrees btd, WOW!!!!!!!!!!! omg the truck feels totally diff it has way better throttle response, low end and sounds better too, but i still have no top end or mid range, yeah i know i need those 4:88s gears in my axles..........  

rebuild the 400. i have a 400/406 in my 1970 chevy k10 pickup with 35s and i have about 2800 invested in to my motor with flat tops and my stock heads are planed to the max with 65cc chambers i have a pretty radical cam in it i couldnt tell you the specs right off hand i wourpm ld have to dig out the build sheet. but i put moly rings in it and all arp bolts. i run it in alot of thick mud and i push her to about 6200-6500rpm it has a eddie airgap duel plane intake and a 750 eddie on top and with the right timingi get 402hp and 500 lbs at the flywheel and it is still strong as ever fiv e years later in the same truck i also daily drove it to work for three years so for the bang for the buck i would stick with the small block unless you have $10,000 justlaying around to build a tough big block  

wow sounds like a sweet motor but i already found good 350 to replace it  

The problem was with the 400's was overheating do to thin clearinces of the waterjackets and cylinderwalls do research before you rebuild it. There is aftermarket blocks for this big small block. If you went with a bigblock and had 350 running gear?  You will most likely break things from the torque of the bigblock.  

I would do a 383 before a 377 because you want torque more than rpms. There are 383's that turn 8k rpms. but your looking at a 7500 dollar motor. I would do a leakdown test to see if your rings are on the way out if it blows black smoke under hard excelleration that is mostlikely what it is. if it smokes just when you start it up it's valve guides. If it's something else carb,timing etc. and you don't need a rebuild get a set of the new vortec heads that are made to accomadate large lift cams, As were the old vortecs had to be machined for large lift cams you can't beat these heads  off the top of my head 389 ea. brandnew it's a instant 20-40hp! gain over stock heads  

yeah i rebuilt the heads hoping that was all the motor needed but it turned out the bottem end was loose too so now im replacing it with an 87 350 with aluminum heads some internal mods and a edelbrock 650 carb, im probabley gonna rebuild the loose 350 later into a 383 and make it really mean unless i decide to stick a big block in the k5 blazer later and build up a big block rather than the small block