Hey guys, I've been having a bit of a think about what path I'm going to take with the ED Sprint (leave it stock?!? Whaaaat?!?).

It's a factory manual, stock 3.27 diff with genie tri-ys and a single 2.5" exhaust.
In the next month or so, the single 2.5" is being ditched for a twin 2.25" system with an x-pipe, mostly for the noise.
Not having a clue with the 5Ls yet, I've been trying to piece together a simple combo, that'll hopefully get me towards a goal of low 14sec quarters.
Haven't run it down the strip as yet, but once I get the "base" time I'll start to put plans in motion.

Anyway, what I'm thinking at the moment, is TFS1, TF upgraded valve spring package (TFS-2500100), YT adjustable 1.6RR (adjustables allow me to keep stock pushrods correct? and the stock 1.7s will have too much lift with the TFS1 anyway? thought about 2031, but have heard of another sprint owner not getting much of a gain with it), BPT underdrives, ditch clutch fan for thermos and a twEECer to top it all off.

Any opinions on whether that will get me to my goal?
I'm hoping the stock MAF and 24# injectors will get me there, am I dead wrong?
Am I flogging a dead horse persisting with the stock GT40 heads?
Is there a cam better suited to the GT40/Cobra setup?

Looking forward to hearing some opinions guys.
Cheers,
Jared

I think you might need a bigger throttle body unit, and maybe a bigger MAF unit too, to keep up the airflow, to go with a bigger cam.
The trouble with those 5lt donks is they cost so much to get them to go.
You can spend less on a 4lt and it goes better, I'm talking N/A engines here.
Look at std EB/ED XR6 vs the XR8's, put better exhausts on either of them, and the six starts to get in front on the 1/4.
Anyway, have fun.

too keep costs down i would go a set of 1.72 RR's (to make better use of current cam, can always get bigger cam to suit later), get Gt40's ported well and shimmed for up compression (not too much), maybe bigger valves if $$ permit, and lower intake ported and matched, good intake filter, drill out airbox, and then a good edit last. run on PULP. good choice with thermos and UD pulleys. should get reasonable gains for well spent $$ and simple mods - 30 - 40rwkw

bigger TB and MAF not a big gain for $$ IMO.

if funds still good, then go a cam swap. i myself am leaning towards an XE270HR for my engine upgrade. jump on comp cams site and have a look at articles on these grinds. good numbers with right head flow.

Could prob steer towards up'ing the diff gears also.

1.7RR is stock on the Cobra spec motors.

Way I'm thinking is a cam is gonna be the best 'bang for buck' on the cobra spec motor.
Think I'm gonna go ahead with it, don't really want the downtime thats gonna occure with porting stock heads, plus I'd probably go alloys over porting stockers anyway.

just be careful that cam can 'keep up' with rest of engine - intake and especially heads, so don't go too big.

alloys a good choice but $$

Pull the heads, knock off 30 thou, get pacey extractors, find a T3 cam, install it adv 6 deg and you will be looking at low 14's all day. Your throttle body/maf/injectors will work just fine. Compression, and cam will help no end.

Your inj's, MAF and stock 70mm TB should handle your goal with some potential left in reserve.
If you ported the stock heads you have now you would definetly take advantage of the better fuel / air capability you already have with your TB, Intake, Inj and MAF. ( I'd suggest porting the lower intake though, all stock GT40 lower intakes are cast with the same annoying air velocity restrictions - especially runners 1 & 5 )
I'd definetly agree with you that whatever cam you choose will be the biggest change and bang for buck.