EFI conversion

Olds 307 and 403

Active member
Oct 4, 2018
212
65
28
Melville, Saskatchewan
Along with the stroker 403 upgrade, I plan on the Sniper returnless EFI module. Of course that means replacing any chunks of hose in the system but not adding a return line. I like the idea of the Qjet flange Sniper with the fuel line positioning and air cleaner positioner for a factory style air cleaner but the extra $200 and 85 less cfm/150 hp, means it is probably a no go, just the regular 800 cfm, 650 hp in gold. I know DoubleV raised the issue of reliability of these systems, any feedback is welcome. So far reviews have been mostly positive. Thoughts?
 

rfpowerdude

New member
Dec 19, 2018
21
4
3
Palm Bay, FL
I'm gonna do a Sniper after the holidays trying to get it done before summer. I looked at the spread bore version too, but I am gonna go with the 800 cfm gold one instead. I have an Edelbrock intake so it will take the square bore Holley style. I already have a Walbro in-tank pump (GN tank) so it should not be hard to get this installed. I say go for it.
 

Olds 307 and 403

Active member
Oct 4, 2018
212
65
28
Melville, Saskatchewan
I also plan on using a RPM intake with the divider cut down, so just the thin plate will be needed for the dual pattern SBO intake. The Holley direct fit fuel pump is nice and no return line is awesome being mine is only the single fuel line, non A/C car. I have another Qjet but this motor will have more compression and cam and I want it easy to drive for my wife or daughters, not that they will very often.
 

Matt69olds

Member
Oct 8, 2018
81
62
18
Kokomo Indiana
I put a sniper on my car 2 years ago. For the most part I’m happy. I wish I know the Super Sniper was going to be available before I got the sniper, the added input/outputs would have been a better fit on my car. It’s a pretty easy install.
 

Olds 307 and 403

Active member
Oct 4, 2018
212
65
28
Melville, Saskatchewan
I figured the fuel pump was the biggest challenge, now it is easy. I like that it can turn on fans as well. I am probably going with an 1 1/8 two core rad aluminum rad with the stamped tanks, the 403 bored .039" over will need it. I also like that it has the ability to run without integral timing control but will convert eventually. I will also get the progressive linkage that should come with it.
 

Olds 307 and 403

Active member
Oct 4, 2018
212
65
28
Melville, Saskatchewan
There have been some issues like touchy throttle and the need for the progressive linkage. I figure I need another Qjet custom tuned, I am almost half way to the base setup. The Holley drop in module for my 70 also makes converting much easier. Any good or bad, please chime in.
 

1bad79

New member
Oct 3, 2018
23
10
3
United States
I really love quadrajets mostly because everyone else can’t get them to work right lol and there just an awesome design but I’m thinking my next build is going to be fuel injected
 

Olds 307 and 403

Active member
Oct 4, 2018
212
65
28
Melville, Saskatchewan
I too like the Qjet, ran them for 30 years. Having the choke issues I had this year has really made me consider EFI for the 70. Holley's drop in my stock tank, returnless 58 psi fuel pump, considering my car doesn't have one, that hooks right up to my factory gauge is a no brainer. Basically I just need efi clamps and hose anywhere along the line, 50 year old stuff anyways.