I am getting a 79 351W full engine the heads were rebuilt in 97 the engine is been out about 5 years and the guy goes out and starts it every two weeks.... that all aside I want to go 408W this is for a daily driven street weekend play toy so dependability is key and simplicity i don't want to completely break the back, i have a 306 full roller now and i like it its just that i have been a long time 351 fan since my first truck and all my muddin experience's while living in washington state, and I'm just hooked on it. SO my questions are being that I DO NOT want a carb, set up i have a set of 24lb hr injectors and the maf from my 306 and the 255 lph is it fees-able to use the 351 lower and the 302 upper or is this not possible, also i have a set of long tubes that were on a set of gt 40p heads now they are on my e7te's can i use them. Also should i keep the 351 heads or use the e7te's from my car i plan on porting and pollishing which ever set of heads that i keep. also i am using a t5 tranny and spec clutch but i do have the availability of of a c6 that i am getting with the motor.. I've heard bad things about the horse power absorption of the C6 so i have pretty much discarded that idea, On those notes here is what the car is being built for....
I want a car that i will not have problems with when i am done, i drive 44 miles each day top speed of the roads that i travle on are 60mph but sometimes and we all know that we do it i run late, and i got to get on it this being a good thing because the roads that i drive on don't have any cops on them lol thank god. I know what its like to be affraid to run the car to high. presently the car has an aod with no overdrive and 3.55 gears at about 55 im pushing about 2800 rpms that being said i don't want that with the 351. And then on the weekends i go out and meet up with some friends and do a little of friendly competing. You all know what im talkin about... any input is greatly appreciated and much needed. thanks in advance for all the input. "i hope i get"

 

The long tubes will not work with the 351 because the block is wider so there will be even less clearance trying to run them with it.
Do not run a c6. It is very heavy, very parasitic and very not needed in your application.
Both the E7's and the stock 351 heads suck so do not run either one of them. I would recommend at the VERY LEAST a set of GT40's. They are still too small in reality but they outflow both of the above heads. The E7's will not work anyway because the head bolt holes are too small for them to bolt on.
From the sounds of it you are trying to get it put together with as little money as possible. So on that note google 95 lightnings. 351w with GT40's, GT40 lower intake that will bolt up to a Cobra upper.

 

I have a 408 in my car and it is a blast to drive... I see no reason why you couldn't use it as DD. You can get the trickflow 351 lower for under $300 and find an upper pretty cheap.
I sent you a pm about some stuff you might be interested in.