I'm replacing the timing chain & gears in my 351m and decided to consider a cam while I've got the cover off. I'm not looking to race the truck, but would like to wake it up some without breaking the bank. I'm still running the stock carb & intake. Dual exhausts with glasspacks, stock manifolds. Now the questions:
What would be a good affordable cam if I do a lot of highway driving?
Will I need new lifters?
New cam bearings?
Valve cover gaskets?
Anything else I'll need?

 

Yes, new lifters. Front cover set and valve cover gaskets. There are plenty of good rv style cams out there. Get the matching valve springs, retainers & keepers for the new cam. Make sure to check lifter preload with the new cam. Use plenty of cam break in paste and add a bottle of cam break in oil, don't let it idle for 20 minutes after starting it. Cam bearings should be ok.

 

like Mark says, 99% sure you'll need to change out the retainers and springs for any aftermarket cam. it'll also involve pulling the intake to get at the lifters

what kind of cam would you say you're looking for; economy, stock replacement, econo-performance, street performance, off road...

and you're going to stay with stock intake/carb/exhaust manifolds and torque converter or is it a stick trans?

 

I would like to avoid changing out parts that don't have to be changed because I'm on a tight budget. Once I add intake, carb, etc., the cam swap gets expensive -- and no longer is an option. I may be better off just doing the timing chain set for now, waiting, saving some money, and doing the cam all at once. The truck is a stick by the way.

 

there's no reason you can't or shouldn't use all the stock stuff mentioned earlier, but it makes a difference in your cam choice. yes, a cam swap alone can be relatively expensive on a tight budget, and even moreso when it snowballs into a bolt-on fest

what are your plans for installing the timing set, at zero or +4* ?

Bubba shows that a 1977 351M should have the D4AE-6250-A cam in it
http://web.archive.org/web/200507290...s/parts03.html

D4AE-6250-A is very similar to Comp 255DEH but the intake opens 5* later and the exhaust closes 10* later http://www.compcams.com/Cam_Specs/Ca...?csid=850&sb=2

i'd say your stock cam is a candidate for the 4* advance position if you wanted to add a little pep at low end. i doubt the highway characteristics would suffer and will probably increase mileage

 

Wow good info grclark351,

I too am in the same kind of bind, I have done a Holley Street Dominator intake and a Edelbrock carb to my 400M, and I was not that pleased with the performance increase I have recieved. So I figured I better make sure the timing is set straight up. Well it already was set at 0, so I was thinking about just yanking the heads off and doing a cam swap. But I may try the 4* advanced setting.

All of this is to an engine that is going to be replaced later this summer for my Built 400 and the 400 I am currently working on is going to be given to a buddy for a project he is working on so I would like this one to perform pretty good

any suggestions? just looking for more power out of this thing

 

take a look at the specs for your cam in the Bubba link and decide whether it's enough cam to do what you want it to, they're not performance cams by any means but may respond to a little tweak

have you done any carb tuning with the metering rods yet? if it runs good at idle and mid-range, maybe try a metering rod or adjustment that riches up the power range. keep notes so you can undo changes that you don't like

ignition advance can unleash hidden usable power and excite the drivability factor, but too much of anything usually isn't good either. try bumping up the base timing a couple degrees if you haven't already, and not just by ear. again you need to know what changes you're making so you have repeatable info and a reference point for when you've gone too far and need to go back to the sweet spot. don't make a decision based on 1 test drive, make an adjustment and drive it for a bit, then make another adjustment if you want. hot/cold and dry/humid weather has an effect on ping so you could think you've found 'it', then the next time it gets dry and up around 100* you're pingin all over the place, or can't get the thing started hot because of too much timing

 

I have bumped the base timing up 6* and have not had and pre detnation. Although 8 gave me some detenation with a load on a steep grade. but I backed it of 2* and have not had any troubles yet.

I have adjusted the step up spring and rods, When I first ran the carb it was waay out, but now it is just slighty rich in full throttle and idle and cruise is a tad lean.

If I Mod wants to eliminate my thread Hijack no probs from me on starting a new thread so the OG poster can get his issue dealt with

 

Just checked and I have the same cam as listed above, I think I may try the 4* advanced position and give it a go. and if I dont like it well I can just drop the edelbrock performer cam in it yard the heads and do springs and retainers.

 

grclark 351, That sounds too good to be true. I have the timing chain already and was going to install it at 0*, but if advancing it to the 4* mark will give me a little extra with no real downside, I think I want to try it. Is that all it really takes? (Until I finally have to rebuild the 150K engine?)

 

i'd give it a go. it's such a small change you might not even notice unless the old timing set was totally whipped to begin with. what i notice when i replace a whipped timing set is that the engine fires up much easier

 

I think I will -- thanks for the great advice. The truck starts pretty easily, but I'm thinking I should notice a difference since as far as I know, I'm still running the stock timing chain -4*, right?

 

Yea From the research I have done if it is the stock chain set then it would be -4*.

Post up how your truck runs after the 4* advance setting I am going to give it a go as well

 

I'm going to give it a try as soon as I get the time. I'll post back here when it's done -- probably a couple weekends away though...

 

I am going to try and get mine done before the weekend, I have mine torn down but it is raining again, so I may get back to it before the weekend. When I get it down I will post up