im in the process of rebuilding my 78 400 and its time to decide on a cam/lifter/spring combo. Im not looking for a huge cam because im using GM tbi. has anyone built a 351m/400 with a mild cam and tbi? Im using a 727 computer out of an 88 c1500 5speed 5.0. I am thinking that the 5.0 injectors and computer are to small for the 400 especially if I ditch the stock bump stick. thoughts? will a 350 computer and injectors simply plug in and work if the 5.0 ones prove to small? thanks for any suggestions!

 

shouldn't matter which ecu you use, as far as i know gm used the same system on engines from the 4.6 to the 454 just larger injectors. i think i read not long ago that the gm tbi could handle up to like 400hp with the right injectors, i'll look around and see if i can find the link. you will have to have the ecu programed for your engine setup.

 

thanks that would be helpful. Im figuring on needing a tune, im just trying to do my homework and find tge perfect combination of parts now, so i don't have to pull the engine apart after its in the truck. im pulling my hair out trying to decide on a cam, and if the tbi is even going to run right at all without a tune at first. its a lot of variables to try and work the bugs out of....or im over thinking everything, whiiich I tend to do haha.

 

yea i hear ya on the "perfect combo". i have considered the tbi conversion myself and from what i've read they behave alot like a carb its the program on the ecu that has to be changed. you just build your engine how you want it(higher compression, heads, cam, ignition) and then the ecu can be programed to match that setup. also the chevy tbi does control the timing so you wil have to convert your ignition or program it not to. i can't seem to find that link that had all the swap info but what i've read these are the guys to talk to about it
Howell Engine Developments, Inc.

 

I've actually got a very strong background in automotive electronics, my harness and distributor is pretty much done and just waiting to wire it into the truck. Im using the GM ecm to control the spark. I just talked to a friend who tbi'd his 57 chevy, and its def not a stock engine. he has no complaints on the way its running. I asked him to send me the specs on his cam just to get an idea for mine. I also talked to the machine shop today that is doin my engine, and I should know by monday if my crank is worth saving. Im thinking its cheaper just to buy one. any suggestions on where?

 

i assume your asking about a crank. lets see RockAuto Auto Parts has remans from 150-300. there is also this site don't know if you can find anything here. Car-Part.com--Used Auto Parts Market there just isn't a main streem of aftermarket support for our engines, stuff is out there but sometimes you have to do some digging. oh there is tim, (TMeyer, Inc. Precision Automotive Machining) prices are good for what you get but not exactly "budget", but he is THE MAN for these engines. i sometimes go there just to drool.

 

m.summitracing.com/parts/cca-k32-206-3

 

I think im goin with Comp cams pn: K32-206-3. I tried posting a link but my phone is retarded. I will check out those sites now.

 

what are your plans for the engine, offroad, towing, daily driver that decision goes a long way in picking the right parts. what other parts are going in and on it as well.

 

mostly im going to be using it as a daily driver, occasionally towing and hauling.

 

that cam is mild but the description claims its more for higher end hp at the cost of low end torque. not really the 400's area to shine. i would look more to the comp high energy line. i've read lots of threads here of people using the cl32-221-3 or something a little milder the cl32-218-3. the high energy's are more for low end which is where the 400 makes its power. also i think those timing sets that come with those sets might be the oem 4* retarded ones not sure, but i would check before you buy.

 

I was asking myself the same thing, however I found more people recomending a dual profile cam lets this engine breath better due to the restrictive exhaust ports. couldn't I degree the cam to shift the powerband lower in the rpm? just a thought. I could be wrong, but I didn't think any aftermarket cams were retarded.

 

I put an Edelbrock Performer cam in my 400, straight up and have been very happy with it. IT has been way too many years to remember the numbers, but it came in the carb, cam and intake kit.

Robert