I have two stock rebuilt slants.
Motor A has:
.030 over bore
windage tray
.450 lift cam
double roller timing chain
stock late (hard seats) head with 3 angle valve job
.050 taken off head
clifford 4BBL intake
Holley 390 carb
mopar perf. electronic ignition and dist.
dual outlet headers that are thin from rust
had motor running once in dart/4speed and 3:23 gears
seemed slow for what it was, but was not dialed in yet

Motor B has:
.060 over bore
.050 taken off the deck
everything else stock on shortblock
1970 head with hard exhaust seats installed
stock 2BBL setup
new carter carb
stock electronic ignition and dist.
runs great and gets 18+ MPG doing mixed driving
car is slow (70 valiant 904/7.25 dont know gears)
have a 8.75/3:23 gear to put in valiant

HELP! any ideas on my best combo for my Valiant, I want more power with driveability,and run on pump gas, I am willing to mix and match please give advice. I love this forum.

Joe

Dial in motor "A". It might surprise you.
What do you consider slow?
Paul

I would use the "A" motor and tune it up.
Nice combination, however Dutra Duals might be nicer to have instead of the shorty headers.

_________________
Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I would vote for motor A, also...the problem with the MP distributor is it's strictly for the track...it's maxxed out by 1200 rpm and the springs are so light the weight pegs bounce off the end of the slot in the governor giving you bad misfires at idle and at low street speeds...pulling this guy apart and swapping in set of heavier springs will help things out greatly...
This car should run 15's all day and maybe into the 14's if you get it all to 'jive'.


-D.idiot

Thanks for the help I know wich motor to use know.
Does anyone think I should pull the milled head and use it on the milled block? Will that be to much for the street on pump gas? Will the increase in compresion be worth the swap? I read about others milling this much off, this will work for me if it will run on premium without spark nock. Any thoughts?

This would all depend on how many CC's the chambers are between the two heads, and how far in the hole the pistons are at TDC...just using the 'decked the block .050' is not good enough... (this could net you a deck height of anywhere from .135 or worse to .095 best case scenario...)

Once you know these two numbers (pulling head and using a syringe to fill a chamber with water, and running a couple of pistons up to TDC and using a caliper to measure), some of us on here could run the numbers to give you an idea based on what is known...be warned if you use a Felpro head gasket, you are giving back about .040)


-D.Idiot

That will be my next step then, I will pull the head on the 2bbl motor since it is leaking oil anyway and check the deck height and cc the heads. Thanks for the input I am going to put a 4bbl motor together with the parts that I have. im not crazy about the headers so I will be looking at a set of dutra Duals. Thanks again.

Did you degree-in the cam on either engine?
DD

I got each motor with a car but I dont think the cams were degreed. I have only degreed two cams in V8's and they both came out right on. Do you think this is needed for this motor?

I have build a lot of SL6 engines and have to adjust cam timing 50% of the time. (I always degree the cam when building an engine)

At this point you should pull the valve cover and see how well the overlap event is centered over TDCEx, doing that will tell you if there is a major cam phasing issue.
As you know, a cam that is not "in phase" can make the engine feel sluggish in certian RPM ranges.
DD