is everything a direct swap from the truck intake? how would this compare to a gt40 lightning intake-hp/tq wise?

 

If you are referring to the performer truck intake then yes it's a direct swap. The car version of the performer should work as well as the GT40.. maybe even a bit better due to a better shaped runners in the lower portion. Power gains with either are impossible to say, depends what else is done to the motor.

I'll add that the intake should not be the first thing upgraded on these motors, the stock intakes are more than capable of flowing more air than the heads can, and you won't see what they are capable of doing until the exhaust is replaced and the cam upgraded.

 

5.0 h.o cam,gt40 heads,1 5/8 shorty headers,2 1/2 exhaust,wanting a good puller/decent performance-i've been thinking about a typhoon intake but i'm unsure of it's pulling ability? being gt40 lightnings are hard to find/pricey and so is $600 for the edelbrock truck efi. i wonder if the stock intake will hold it back,any porting potential with these? i just don't want the motor holding back and peaking at 4500-that would be a waste of decent heads/cam

 

The Typhoon/Performer and GT40/Explorer intakes all have pretty long runners, not much shorter than the stock truck intake(like only 1/2") so low RPM power won't be an issue on a 351.

The good news is yes there is porting potential in the stock truck intake. The bad news is any head smaller than the AFR185 is "holding back" a 351, so either one of these intakes will do just fine.

 

you don't think i'm leaving any power on the table to use my stock intake-i've always heard the upper is a big choke? i wish someone had some flow #'s on this intake,that would make my mind up. i'm thinking typhoon-seems to be the best buy

 

The stock intake is better than everybody gives it credit for and will make this motor a real stump puller. If anything the lower will be the choke point so I highly recommend port matching the lower to heads. It would only cost you a set of gaskets to try it out, I think you would be surprised how well it works. Extrude honing it would certainly inprove it's potential but you can get a Typhoon for less than that would cost.
Even with the GT40 heads I think the motor will still peak at about 4500rpm, I believe this is where the G1 Lightning made peak power and what you have will be similar.