hello all

I am building a stock F-body LT1 motor for my 1986 GMC 4x4 shortbed pickup
and I want it to have great low end torque for sand dunes climbing + mudding + have good milage

now the truck has stock 350 + SM465 tranny but I'll add long tube headers 1 5/8" + cam + ( and springs if required ) with the new motor

and I won't rev it higher than 6000 rpm

Comp Cams suggested this cam for me

http://www.compcams.com/Technical/Se...umber=07-502-8


do you know any other cam that in comparable / better than this one ?
and is it true that 1.94/1.5 valves is better than 2.02/1.6 for low end torque ?

thanks

 

What sort of gears and height tire are you running? That cam is large enough to hurt low speed power if you have big tires and not enough gear. On the valvesize these heads stock with small valves completely blow the old big valve stuff out of the water flow wise and can be made to flow bettewr yet with porting but without bigger valves, for all out then larger valves can be considered but for a mild build spend the money elsewhere.

Are you planning to run the LT1 injection? If not don't bother with the LT1 the biggest strength of the LT1 is the heads flow a good bit better than anything GM made before them and the Vortec heads from the 96 trucks were modeled after some of the LT1 heads so just a set of those would bring your gen1 motor up a long ways in power. Wether you are injecting it with the LT1 system or running a carb will affect cam selection too because the LT1 intake with it's ultra short runners moves the powerband up a few hundred rpms over the same setup with a typical dual plane intake.

 

What he said.

Plus...
That's the perfect application for an inexpensive 383 stroker kit with a cast crank. Maybe that's still not in the budget, but summit has a basic cast crank stroker kit for under $1,100.00. If you can swing it, do it.

 

Put a RV cam made for towing in there,it will have plenty of low end grunt.

 

I have the cam they recommended.I think you would be happy with it,great low end grunt!

 

Crane 227, part # 104227 if you want to look it up on their site. That thing had power from idle-6K.

 

Yeah the Crane 104227 is a very good cam for staying below 6K some very fast Impalas have run that cam and some fast Camaors too but most here prefer to be able to claim big duration numbers even when they don't go any faster than the "smaller" cams.
The Comp 502 might be a good cam in an f-body and might exibit adequate lownd torque in such but a offroading 4X4 is a very differnt application 4 driven wheels in sand with a stick is going to want real stump pulling lownend.

 

any pics of the truck!!! mudding=

 

LT1+mudding = dead opti. I've read it a million times on the jeep forums i frequent(i own a jeep along with the Z). People plop an lt1 in their jeep, take it out mudding, and kill the opti.

 

now it has 3.08 gears and I might swap in 3.73s later
the tires are 33"x12.5"x15"

and yes it will be fuel injected but I will use megasquirt II ( speed density ) to control injection + ignition
and I will drill the back of the intake to use HEI dist. so no opti for me




I'de love to do a 383 but now I don't have enough cash to do it


so the 104227 will give me better low end than the 502
is there any dynosheets for both cams ?

thanks a lot

 

also .. can I use all SBC brakets & accesories ( including SBC damper ) on LT1 block

 

3.08s and 33" tires you will not be happy with something as big as the Comp 502. It is similar in size to the HOT cam the b-body crowd(comparable due to weight) considers 3.42s bare minumum with with the HOT cam with our 27" tires with 3.73s being prefered, with your tires 3.73s would be marginal with 4.10s being better so pick a smaller cam.

Honestly if you don't already have a motor you might consider picking up a b-body engine and leave the cam alone. The b-body cam makes more peak torque at a lower rpm than the f-body cam, people will knock the iron heads but they choose to ignore the fact they outflow most of the aluminum and only the best aluminums equal them in stock form. If you are looking to port heads though the b-body cam will not support ported heads just not big enough. Full bolton b-bodies with good tuning and 1.6 rockers have put down 300RWHP with high stall converters with absolutely no need to hit 6K.

 

I don't believe that you can. The Lt1 water pump is mechanical, but is driven by the cam....so there is no pulley...also the pump is bigger. That being said, I don't believe that it will work to have the brackets on both sides. An LT1 accessory bracket would work great, as well as clean up the engine bay some...its all on the PS if its from a F body. On the LT1 the damper is also the pulley, so I don't believe you can interchange them.

I also agree that you won't be happy with those 3.08's and 33/12.5 tires. Your gonna need stump pulling torque just to get her moving....even more so with sand under the tires.

 

An Accel 74211 cam would work great for your mudder application. It has a 211/219 duration with 525/560 lift. It makes HUGE torque in the bottom and mid range. Lingenfelter used these cams in their 383 engine packages and its a great cam replacement for the stock LT1 engine.

I would be very careful with the OPTI, if you get a bunch of water on it you had better be prepared to walk or have lots of friends around to tow you out.

 

I have the motor already but less the accesories & bracketry and I am thinking in selling it and buying a complete B-body motor

regarding gears
I haven't bought anything yet and I will start searching for cheap 4.10s