Cam for this project

[gordon]

After a long interruption from progress on a 383 engine for my brother 58 GMC truck I need a cam , lifters, rockers etc. Here is what I have to work with so far. 1988 roller 350 block .030 over. forged pistons ,20cc dish. 6" I beam rods, 3.750 cast crank. Set of TFS aluminum camel hump heads, 2.02 int. vlv. , 1.60" ex vlv. Int runner 175 cc exh port 74cc Combustion chamber 60cc. After mocking every thing up and measuring , pistons are down .019 , I will be using steel shim gasket that will end up at .015" crushed,. Allowing for crevice volumes and such I come up with 9.98:1 on the compression ratio. The heads according to TFS ( I no longer have my superflow to verify but an working on purchasing a SF600 this summer(older used one)) Advertised flows are lift int cfm ex cfm Edelbrock rpm air gap manifold and 750 Edelbrock carb . 1 5/8" custom headers.
Very free flowing exhaust system using four mufflers in parallel .
.100 65 53
.200 133 104
.300 192 136
.400 233 180
.500 258 198
.600 254 207 28" of water (pressure)
bore size for test 4.030"; exhaust with 1 3/4"pipe
The truck is a 58' GMC fleet side should come out to 3600lbs. 12 bolt W/3.73:1 RP , Transmission is a 4l80e with electronic controller . Gear ratios are
2.48 1st 1.48 2nd. 3rd 1:1 and OD .75:1 plus lock up converter.
Hope to run on pump gas in Hot Fl weather , not a race car but fun truck for 63 year old that likes to drive old trucks even long trips out west.
Ok I think I have listed every thing that usually gets ask.
I am looking at two of Howards cams offerings First one is listed 272/278 @.050 219/225 .525/.525 w/1.50 rockers on 112 LSA /installed at 108
Second 266/270 @.050 213/217 .485/.495 " " " on 112 LSA/ " " 108
Was thinking of getting one ground from Howards as a single pattern 272/272 @.050 219/219 .525/525 " "" " " / 108
Target 375 HP 400+ TQ good manners , good fuel economy (18-20) on freeway. good vacuum and Idle for AC and maybe power brakes. Not likely on power brks. A/C yes
Am I close on cam numbers?

[lefty o]

as i was reading, i thought this is about the perfect combo for the old gm "hot cam" nice little hydraulic roller.

[BillK]

Sounds like you are ok with Howards. I would cut and paste this entire thread into an e-mail and send it to Eric and see what he suggests.

[gordon]

Is there a reason I should not be ok with Howards cams? I used to be satisfied with cams from Harold Brookshire and heard the Howards cams and Bullet cams use many of Harold's later designs. There are some very experienced builders on here and I hope to hear from them on the subject. Calling Howards cams only gets me one recommendation from a sales person. If you have negative experiences using Howards products , state your case with facts and leave it at that. I never said Howards was my only choice , I was listing those numbers as an example . I used to get really good results with roller cams from Madden for inj BBC. Madden is no longer around. Crane is no longer Crane so I am looking around.

[F-BIRD'88]

Since its a oem hyd roller block why not use a hyd roller cam?

Eg: Melling 22280.. look it up.. Could install on a torquey
104/116 phasing. "Truck TorQ"

Nothing wrong with Howards stuff.
Your Howards picks look good.

[F-BIRD'88]

While I like to use the .015" steel shim head gaskets on cast block cast iron head sbc builds you may find long term the aluminum head may see galvanitic corrosion effect with this gasket.. (dissimular metals)

[gordon]

Yes my intent is to only use Hyd roller since the block is already set up that way.

[rustbucket79]

I would have no issue with your first selection.

[rebelyell]

All good suggestions
Unlike too many others' cast/sadi iron rollers, Summit has recently introduced their own house selection of 4 STEEL billet rollers on 112 LSA; all under $250 ... check out Stages 2 or 3 or 4.
https://www.summitracing.com/search/pro ... =Ascending

[CamKing]

This will peak HP at 5,300rpm, with over 400hp.
It'll also make about 430ftlbs of torque.

Cam# HR68340-69340-110
216/220 @.050"
.340"/.340" Lobe Lift
110 LSA

It ain't cheap, but you get what you pay for.

[RevTheory]

The problem with combos like this is that a heavy truck with larger tires swallows up all the power you can get from a 383 unless you build it snotty and that tends to take away from what you'd intended. I guess you have to decide what you're ok with and let it be. I'm having this very fight in my mind as we speak.

The last 383 I did for a heavy truck made 482 ft/lbs but it was a snotty prick and took away from what I really wanted. It was snappy and roasted 35 inch tires at will but you couldn't see anything out of the mirrors at a stop light and it felt like a damn race car. Running the a/c was a no-go.

[gordon]

No tall tires being used here. Most likely 27-29" at most plus either 3.73 or 3.55:1 gears in a 12 bolt. OE converter loosened up by about 200 rpm.

[F-BIRD'88]

Those are Tall tires and with those gears for a truck that will be a lot heavier than #3600 . More like 4000#++.

There is one thing building a hi perf engine ,but gearing it correctly to make use of said engines powerband to get performance from a big vehicle with big tires too, is another thing.. This is where most get it wrong.

With that consideration I'd keep the cam choice shoe size right around CamKing's recomendation if with 3.55-3.73 gears and 27-29" rubber.

Where as my Melling cam and the similar larger Howards cams picks will want
4.10 to 4.30 gears with same 27-29" tires.

Truck hyway cruiseing RPM @75 MPH in OVERDRIVE has been calced into this, as well as getting strong TRUCK acceleration.

[F-BIRD'88]

The problem with combos like this is that a heavy truck with larger tires swallows up all the power you can get from a 383 unless you build it snotty and that tends to take away from what you'd intended. I guess you have to decide what you're ok with and let it be. I'm having this very fight in my mind as we speak.

The last 383 I did for a heavy truck made 482 ft/lbs but it was a snotty prick and took away from what I really wanted. It was snappy and roasted 35 inch tires at will but you couldn't see anything out of the mirrors at a stop light and it felt like a damn race car. Running the a/c was a no-go.

This is the very reason I recomend supercharged sb builds for these trucks VS hot N/A builds. The supercharged engine has the real power and torque required while being of a more street friendly less "racey" engine combo.

Trucks are big heavy and a supercharged engine gets it done better, when IT comes to getting that big non areo dynamic hunk moving quick while still being "street ABLE"