[jumbo2]

I have a .30 454 with forged domes 29.7cc and am running stock 781's so comp should be 9:5-1 , also picked up some comp cams retro hyd roller lifters for a song and dance in the box so looking for a cam . street/strip use 2500-3000 stall , air gap , demon race 850 and msd digital 6 , big headers and exhaust, 3500lb truck with 9 inch and 3:73 with 31 inch tire , dont care about chunky idle looking for 6000-6200 redline and maybe 150 shot once and a while

comp X energy xr288xr looks good , not sure of the magnum family or if I have to run a comp cam

[cdminter59]

The cam you are looking at XR288HR looks good on the dyno from CamQuest. Also look at 290HR 11-450-8 2500-6200, .578/.578 232/232 432 hp @ 5000 and 502 lbs of torque @ 2500 rpms.

[F-BIRD'88]

pass on the hyd roller cam hyd roller lifters for the BBC and go for the Solid roller Xr280r-10.
Especially with nitrous. Even if free. They are being offered to you cheap for a reason.

Comp XR280r-10 cam and K-kit #K12-771-8
Set the valve lash cold at .012"in .014ex. You will never know the difference from a Hyd roller
except the far superior engine performance.
Once a year simple valve lash adjustment.

call comp cams for tech advice.

The similar Lunati Voodoo solid street rollers rock too.
238 to 244 intake duration is just right.

This snotty short duration Magnum mechanical street roller works real real well too
Comp cams Magnum CB280AR-10 # 11-691-9

280-288 238-246@.050" .623-.623" lift 110LSA
hot lash .020" .020" (set cold lash at .014" to .016")
This old Magnum rocks. Outperforms all Hyd rollers in BBC's
This does have a very cool chunky idle sound Makes huge torque.
drive vey nice on the street. Did I mention huge TORQUE ???
easy no fuss- no hassle valve lash maintenance.
Call comp cams for the right valve springs etc. Big street power and torque.
Your stock 781 heads can use some porting .

BBC's have a heavy valve train and retro hyd roller lifters are heavy too.
premature lifter float and pump up limits top end power. Jacked up spring pressure only gets you so far with a hyd on a BBC.
Not far enough. especially with nitrous.

Again you are being offered the hyd lifters for a reason.

[jumbo2]

can go solid dont have the $$ its either flat tappet or hyd roller , like to be closer to 500hp

[vinniekq2]

a 400 horse rat will make the 3500 pound truck run into the 11s. How did you decide on 500 hp?Buy a set of aluminum oval port heads if you want 500 hp.If you are racing,I would think awhile about camshafts. Are you looking for low or high rpm?If its 6k or lower,use the hydraulic roller.over 6k you should consider a solid cam.Big blocks need a few goodies to live at higher rpm s

[F-BIRD'88]

Originally Posted by jumbo2

can go solid don't have the $$ its either flat tappet or hyd roller , like to be closer to 500hp

The mechanical XR street roller is slightly cheaper all said and done.
The K kits are a great value. And well worth the price.
call comp cams for help.
The Howards mechanical street rollers are very good too.
keep the duration short and snotty 237 to 244 @.050"

Save another pay check or buy the hyd roller lifters and sell them to raise money.
to get the right cam for your BBC.

[F-BIRD'88]

You next best low budget choie is a good BBC mechanical flat tappet cam and lifters.
They work real good too.

The BBC street hyd rollers tend to give up the ghost at 5500ish rpm some as soon as 5200
some 5800. most all al giveing up power by 6000rpm.

You do not want that with nitrous. The new improved limited plunger travel hyd roller lifters Crane etc.
are pricey and require a real good cam lobe design (Crane Hyd roller) and big springs.
now you are into money.

a lot of people that have been down this road end up running a solid mechanical roller lifter and more spring
on their Hyd roller cam to get the nessessary rpm capability . (very small cold lash setting .001" to .004")
Why not get get the right mechanical street roller cam and mechanical roller lifters in the first place?

Do you got enough money to do this twice- three times?

The mech street roller is the good deal ..... net cost and far superior performance in a BBC.
The XR mechanical street roller K kits are hard to beat.

[jumbo2]

Originally Posted by vinniekq2

a 400 horse rat will make the 3500 pound truck run into the 11s. How did you decide on 500 hp?Buy a set of aluminum oval port heads if you want 500 hp.If you are racing,I would think awhile about camshafts. Are you looking for low or high rpm?If its 6k or lower,use the hydraulic roller.over 6k you should consider a solid cam.Big blocks need a few goodies to live at higher rpm s

If there are engine builds with peanut heads making over 500hp why would I swap my 781's out for $2000 aluminums ? without a ballanced engine over 6000 it wont live long so I will keep it under , 11.6 is the goal but dont plan only racing want to have a fun on the street as well

[jumbo2]

Originally Posted by F-BIRD'88

You next best low budget choie is a good BBC mechanical flat tappet cam and lifters.
They work real good too.

The BBC street hyd rollers tend to give up the ghost at 5500ish rpm some as soon as 5200
some 5800. most all al giveing up power by 6000rpm.

You do not want that with nitrous. The new improved limited plunger travel hyd roller lifters Crane etc.
are pricey and require a real good cam lobe design (Crane Hyd roller) and big springs.
now you are into money.

a lot of people that have been down this road end up running a solid mechanical roller lifter and more spring
on their Hyd roller cam to get the nessessary rpm capability . (very small cold lash setting .001" to .004")
Why not get get the right mechanical street roller cam and mechanical roller lifters in the first place?

Do you got enough money to do this twice- three times?

The mech street roller is the good deal ..... net cost and far superior performance in a BBC.
The XR mechanical street roller K kits are hard to beat.

the motor came with a comp 274 hyd flat tappet cam and lifters , I got the roller lifters for almost nothing so my budget allows for a roller cam or flat tappet cam/lifter combo , from all I have read about BBC rounding cam lobes off I cant see how a hyd roller isnt better than a hyd flat tappet

[jumbo2]

XR mechanical K kit if over a grand , that doesnt sound to cost efective to me ?

[F-BIRD'88]

Originally Posted by jumbo2

XR mechanical K kit if over a grand , that doesnt sound to cost efective to me ?

The K-11-770-8 and K11-771-8 kit is $900.

Couple real nice street flat tappets
Lunati (UD Harold design. Ultradyne)
402A1LUN
402A2LUN.
These will rock in your 454 truck with a bit of spray.
I believe the good UD Harold stuff is available thu Howards and Bullet cams too.
easy street manors great power and rpm.

Do it your way and spend more and come up short.
Then do it again.....
or do it right then first time ... once.
Your choice bud..
Good luck.

[vinniekq2]

Unless you put your peanut heads on a flow bench,you really have no idea how many horses you can get from your engine.Porting your peanut heads is not money well spent.You mentioned using 3.73 gears,so you need lower rpm/torque engine.If you use a big cam to make high rpm horse power then your peanut heads will hold you back.
when you have flow numbers you can determine HP potential,,,

[jumbo2]

Originally Posted by vinniekq2

Unless you put your peanut heads on a flow bench,you really have no idea how many horses you can get from your engine.Porting your peanut heads is not money well spent.You mentioned using 3.73 gears,so you need lower rpm/torque engine.If you use a big cam to make high rpm horse power then your peanut heads will hold you back.
when you have flow numbers you can determine HP potential,,,

Maybe I didnt make things clear im not running peanut heads , If peanut heads can make 500hp why wouldn;t my 781's ? I have a good set of 781's and am capable of cleaning them up and even some port polish work

[jumbo2]

[QUOTE=F-BIRD'88;1599050]The K-11-770-8 and K11-771-8 kit is $900.

900 plus tax is $1000 in my books wich is not in my budget , Like I stated I can buy a hyd roller or replace the comp 274 with something else or run the 274 flat tappet , I plan on doing alot of street driving and the odd race track pass

[F-BIRD'88]

I have run BBC's for years. Lost one flat tappet cam in a BBC , after many years many miles of service. 7000rpm. just plain wore it out. Use quality stuff and you won't have problems.